Do not use raw html i18n messages for errors.

The i18n Error messages should be properly escaped. This is not an
XSS as the none of the parameters to the error message were user
controlled (outside of MW namespace)

This fixes the outstanding errors from phan-taint-check

Change-Id: I0b4d6b5eb3e210a131937e65268091ec83f0b434

ImageMap_body.php

@@ -401,6 +401,6 @@ class ImageMap {
 	 * @return string HTML
 	 */
 	static function error( $name, $line = false ) {
-		return '<p class="error">' . wfMessage( $name, $line )->text() . '</p>';
+		return '<p class="error">' . wfMessage( $name, $line )->parse() . '</p>';
 	}
 }