display phone number field only if $CONF[sms_send_function] is set

Without a way to send a SMS, asking users for their mobile number is
pointless.

config.inc.php

@@ -600,6 +600,8 @@ $CONF['forgotten_admin_password_reset'] = false;
 // Please use a name that begins with "x_" to prevent collisions
 // This function must accept 2 parameters: phone number and message,
 // and return true on success or false on failure
+// Note: if no sms_send_function is defined, the input field for the mobile
+// number won't be displayed
 $CONF['sms_send_function'] = '';
 
 /*

model/AdminHandler.php

@@ -36,6 +36,13 @@ class AdminHandler extends PFAHandler {
 
         $passwordReset = Config::read('forgotten_admin_password_reset');
 
+        if ($passwordReset) {
+            $reset_by_sms = 0;
+            if (Config::read('sms_send_function')) {
+                $reset_by_sms = 1;
+            }
+        }
+
         $this->struct=array(
             # field name                allow       display in...   type    $PALANG label          $PALANG description   default / options / ...
             #                           editing?    form    list
@@ -75,7 +82,7 @@ class AdminHandler extends PFAHandler {
                              ' ) AS __domain on username = __domain_username'),
 
             'active'           => pacol(1,          1,      1,      'bool', 'active'             , ''                  , 1     ),
-            'phone'            => pacol(1,  $passwordReset, 0,      'text', 'pCreate_mailbox_phone', 'pCreate_mailbox_phone_desc', ''),
+            'phone'            => pacol(1,  $reset_by_sms,  0,      'text', 'pCreate_mailbox_phone', 'pCreate_mailbox_phone_desc', ''),
             'email_other'      => pacol(1,  $passwordReset, 0,      'mail', 'pCreate_mailbox_email', 'pCreate_mailbox_email_desc', ''),
             'token'            => pacol(1,          0,      0,      'text', ''                   , ''                  ),
             'token_validity'   => pacol(1,          0,      0,      'ts',   ''                   , '', date("Y-m-d H:i:s",time())),

model/MailboxHandler.php

@@ -13,6 +13,13 @@ class MailboxHandler extends PFAHandler {
     # init $this->struct, $this->db_table and $this->id_field
     protected function initStruct() {
         $passwordReset = Config::read('forgotten_user_password_reset');
+        if ($passwordReset) {
+            $reset_by_sms = 0;
+            if (Config::read('sms_send_function')) {
+                $reset_by_sms = 1;
+            }
+        }
+
         $this->struct=array(
             # field name                allow       display in...   type    $PALANG label                     $PALANG description                 default / options / ...
             #                           editing?    form    list
@@ -38,7 +45,7 @@ class MailboxHandler extends PFAHandler {
             'welcome_mail'     => pacol($this->new, $this->new, 0,  'bool', 'pCreate_mailbox_mail'          , ''                                 , 1,
                 /*options*/ '',
                 /*not_in_db*/ 1             ),
-            'phone'            => pacol(1,  $passwordReset, 0,      'text', 'pCreate_mailbox_phone'         , 'pCreate_mailbox_phone_desc'       , ''),
+            'phone'            => pacol(1,  $reset_by_sms,  0,      'text', 'pCreate_mailbox_phone'         , 'pCreate_mailbox_phone_desc'       , ''),
             'email_other'      => pacol(1,  $passwordReset, 0,      'mail', 'pCreate_mailbox_email'         , 'pCreate_mailbox_email_desc'       , ''),
             'token'            => pacol(1,          0,      0,      'text', ''                              , ''                                 ),
             'token_validity'   => pacol(1,          0,      0,      'ts',   ''                              , '', date("Y-m-d H:i:s",time())),