DroidFish: do 'apt-get update' twice

Try this workaround for fdroid/fdroiddata#1404.

metadata/org.petero.droidfish.txt

@@ -184,7 +184,7 @@ Build:1.68,76
 Build:1.72,80
     commit=1.72
     subdir=DroidFish
-    sudo=apt update && \
+    sudo=apt update || apt update && \
         apt install -y proguard-cli
     prebuild=echo 'source.dir=src;../CuckooChessEngine/src' > ant.properties && \
         echo 'proguard.jar=/usr/share/java/proguard.jar' >> local.properties