emulators/citra: unbreak fetch after 66e2037

Failover between mirrors doesn't work if file exists but is different.

=> Attempting to fetch https://api.citra-emu.org/gamedb/?dummy=/citra/compatibility_list.json
[...]
=> SHA256 Checksum mismatch for citra/compatibility_list.json.
[...]
===>  Giving up on fetching files:  citra/compatibility_list.json

Reported by:	pkg-fallout

emulators/citra/Makefile

@@ -2,8 +2,11 @@ PORTNAME=	citra
 PORTVERSION=	s20211218
 PORTREVISION?=	0
 CATEGORIES=	emulators
-MASTER_SITES=	https://api.citra-emu.org/gamedb/?dummy=/:gamedb \
-		LOCAL/jbeich:gamedb
+.if make(makesum)
+MASTER_SITES=	https://api.citra-emu.org/gamedb/?dummy=/:gamedb
+.else
+MASTER_SITES=	LOCAL/jbeich:gamedb
+.endif
 DISTFILES=	${PORTNAME}/compatibility_list.json:gamedb
 EXTRACT_ONLY=	${DISTFILES:N*\:gamedb:C/\:.*//}