Fix sync mailboxes script dicker image

migration/sync-mailboxes.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# Runs imapsync (via the dockerized imapsync/imapsync image) for every account
+# Runs imapsync (via the upstream gilleslamiral/imapsync image) for every account
 # in a migration accounts.csv, copying mail from docker-mailserver to Stalwart.
 set -euo pipefail
 
@@ -35,7 +35,7 @@ while IFS=',' read -r email new_password old_password aliases quota_mb; do
 
   echo "==> Syncing $email"
 
-  args=(run --rm imapsync/imapsync
+  args=(run --rm gilleslamiral/imapsync imapsync
     --host1 "$SOURCE_HOST" --port1 "$SOURCE_PORT" --ssl1 --user1 "$email" --password1 "$old_password"
     --host2 "$DEST_HOST" --port2 "$DEST_PORT" --ssl2 --user2 "$email" --password2 "$new_password"
     --automap --syncinternaldates --skipcrossduplicates --no-modulesversion)