Update SRF_Calendar.php

Replace Language::factory, which has been deprecated since 1.35 (removed by 1.41).

formats/calendar/SRF_Calendar.php

@@ -48,7 +48,7 @@ protected function handleParameters( array $params, $outputmode ) {
 			// Store the actual user's language, so we can revert
 			// back to it after printing the calendar.
 			$this->mRealUserLang = clone $wgLang;
-			$wgLang = Language::factory( trim( $params['lang'] ) );
+			$wgLang = MediaWikiServices::getInstance()->getLanguageFactory()->getLanguage( trim( $params['lang'] ) );
 		}
 
 		$this->setColors( $params['colors'] );