fixed missing query parameter during redirect
Media Gallery: Query parameter get lost during redirect to .php
Example: https://marine-data.de/preview/vef/usecases/gallery.html?site=gallery&filter=event='PS96/090-4'+and+(dataset=862093)&shareID=4301718516723958 -> https://marine-data.de/preview/vef/usecases/gallery.php?site=gallery
@rhess : Were there reasons to use the meta tag for the redirect? Please review and merge before the dev branch goes live.