[BUGFIX][QGIS Server] Add charset for application/vnd.ogc.gml GetFeatureInfo

Author: rldhont

src/server/qgshttprequesthandler.cpp

@@ -112,7 +112,7 @@ void QgsHttpRequestHandler::sendHeaders()
     QgsDebugMsg( QString( "Content format: %1" ).arg( mInfoFormat ) );
     printf( "Content-Type: " );
     printf( mInfoFormat.toLocal8Bit() );
-    if ( mInfoFormat.startsWith( "text/" ) )
+    if ( mInfoFormat.startsWith( "text/" ) || mInfoFormat.startsWith( "application/vnd.ogc.gml" ) )
       printf( "; charset=utf-8" );
     printf( "\n" );
     // size is not known when streaming