Don't abandon a wiki if the main page wasn't edited

Various errors have caused this script to fail, but it
isn't critical, so let the wiki continue to install so
the error can be better debugged.

Part of #385

Author: edg2s

new/postinstall.sh

@@ -4,7 +4,7 @@ set -ex
 # update Main_Page
 sleep 1 # Ensure edit appears after creation in history
 MAINPAGETITLE=$( echo 'echo Title::newMainPage()->getDBkey();' | php $PATCHDEMO/wikis/$NAME/w/maintenance/eval.php 2> /dev/null )
-echo "$MAINPAGE" | php $PATCHDEMO/wikis/$NAME/w/maintenance/edit.php "$MAINPAGETITLE"
+echo "$MAINPAGE" | php $PATCHDEMO/wikis/$NAME/w/maintenance/edit.php "$MAINPAGETITLE" || echo "Can't edit main page"
 
 # run update script (#166, #244)
 php $PATCHDEMO/wikis/$NAME/w/maintenance/update.php --quick