replace double quote with simple quote

Co-Authored-By: troopa81 <julien.cabieces@oslandia.com>

Author: m-kuhn

src/providers/postgres/qgspostgresprovider.cpp

@@ -4342,7 +4342,7 @@ QVariant QgsPostgresProvider::parseMultidimensionalArray( const QString &txt )
 
     values.append( text.left( ++i ) );
     i = text.indexOf( ',', i );
-    i = i > 0 ? text.indexOf( "{", i ) : -1;
+    i = i > 0 ? text.indexOf( '{', i ) : -1;
     if ( i == -1 )
       break;