Don't send complete error page to the spellchecker on error (when pspell extension isn't found)

program/include/rcube_spellchecker.php

@@ -57,13 +57,6 @@ class rcube_spellchecker
         $this->engine = $this->rc->config->get('spellcheck_engine', 'googie');
         $this->lang   = $lang ? $lang : 'en';
 
-        if ($this->engine == 'pspell' && !extension_loaded('pspell')) {
-            rcube::raise_error(array(
-                'code' => 500, 'type' => 'php',
-                'file' => __FILE__, 'line' => __LINE__,
-                'message' => "Pspell extension not available"), true, true);
-        }
-
         $this->options = array(
             'ignore_syms' => $this->rc->config->get('spellcheck_ignore_syms'),
             'ignore_nums' => $this->rc->config->get('spellcheck_ignore_nums'),
@@ -321,6 +314,16 @@ class rcube_spellchecker
     private function _pspell_init()
     {
         if (!$this->plink) {
+            if (!extension_loaded('pspell')) {
+                $this->error = "Pspell extension not available";
+                rcube::raise_error(array(
+                    'code' => 500, 'type' => 'php',
+                    'file' => __FILE__, 'line' => __LINE__,
+                    'message' => $this->error), true, false);
+
+                return;
+            }
+
             $this->plink = pspell_new($this->lang, null, null, RCMAIL_CHARSET, PSPELL_FAST);
         }