fix several cases of Db class being invoked as wrong name (as DB)

classes/article.php

@@ -652,7 +652,7 @@ class Article extends Handler_Protected {
 	}
 
 	static function getLastArticleId() {
-		$pdo = DB::pdo();
+		$pdo = Db::pdo();
 
 		$sth = $pdo->prepare("SELECT ref_id AS id FROM ttrss_user_entries
 			WHERE owner_uid = ? ORDER BY ref_id DESC LIMIT 1");

classes/counters.php

@@ -42,7 +42,7 @@ class Counters {
 
 		array_push($ret, $cv);
 
-		$pdo = DB::pdo();
+		$pdo = Db::pdo();
 
 		$sth = $pdo->prepare("SELECT fc.id,
 				SUM(CASE WHEN unread THEN 1 ELSE 0 END) AS count,

classes/feeds.php

@@ -2097,7 +2097,7 @@ class Feeds extends Handler_Protected {
 
 	static function feed_purge_interval($feed_id) {
 
-		$pdo = DB::pdo();
+		$pdo = Db::pdo();
 
 		$sth = $pdo->prepare("SELECT purge_interval, owner_uid FROM ttrss_feeds
 			WHERE id = ?");

include/controls.php

@@ -74,7 +74,7 @@ function print_feed_multi_select($id, $default_ids = [],
 						   $attributes = "", $include_all_feeds = true,
 						   $root_id = null, $nest_level = 0) {
 
-	$pdo = DB::pdo();
+	$pdo = Db::pdo();
 
 	print_r(in_array("CAT:6",$default_ids));
 
@@ -180,7 +180,7 @@ function print_feed_cat_select($id, $default_id,
 		print "<select id=\"$id\" name=\"$id\" default=\"$default_id\" $attributes>";
 	}
 
-	$pdo = DB::pdo();
+	$pdo = Db::pdo();
 
 	if (!$root_id) $root_id = null;
 

include/functions.php

@@ -485,7 +485,7 @@
 
 		if (get_schema_version() < 63) $profile_qpart = "";
 
-		$pdo = DB::pdo();
+		$pdo = Db::pdo();
 		$in_nested_tr = false;
 
 		try {
@@ -573,7 +573,7 @@
 				$_SESSION["uid"] = $user_id;
 				$_SESSION["auth_module"] = $auth_module;
 
-				$pdo = DB::pdo();
+				$pdo = Db::pdo();
 				$sth = $pdo->prepare("SELECT login,access_level,pwd_hash FROM ttrss_users
 					WHERE id = ?");
 				$sth->execute([$user_id]);
@@ -662,7 +662,7 @@
 
 	function initialize_user($uid) {
 
-		$pdo = DB::pdo();
+		$pdo = Db::pdo();
 
 		$sth = $pdo->prepare("insert into ttrss_feeds (owner_uid,title,feed_url)
 			values (?, 'Tiny Tiny RSS: Forum',
@@ -861,7 +861,7 @@
 	function get_schema_version($nocache = false) {
 		global $schema_version;
 
-		$pdo = DB::pdo();
+		$pdo = Db::pdo();
 
 		if (!$schema_version && !$nocache) {
 			$row = $pdo->query("SELECT schema_version FROM ttrss_version")->fetch();

include/sanity_check.php

@@ -105,7 +105,7 @@
 			}
 
 			if (SINGLE_USER_MODE && class_exists("PDO")) {
-			    $pdo = DB::pdo();
+			    $pdo = Db::pdo();
 
 				$res = $pdo->query("SELECT id FROM ttrss_users WHERE id = 1");