scripts/mkimage.sh: allow --repository multiple times

we dont need --extra-repository anymore but keep it for backwards
compatibility

scripts/mkimage.sh

@@ -201,7 +201,13 @@ while [ $# -gt 0 ]; do
 	opt="$1"
 	shift
 	case "$opt" in
-	--repository) REPODIR="$1"; shift ;;
+	--repository)
+		if [ -z "$REPOS" ]; then
+			REPOS="$1"
+		else
+			REPOS=$(printf '%s\n%s' "$REPOS" "$1");
+		fi
+		shift ;;
 	--extra-repository) EXTRAREPOS="$EXTRAREPOS $1"; shift ;;
 	--workdir) WORKDIR="$1"; shift ;;
 	--outdir) OUTDIR="$1"; shift ;;
@@ -256,10 +262,10 @@ for ARCH in $req_arch; do
 		cp -Pr /etc/apk/keys "$APKROOT/etc/apk/"
 		abuild-apk --arch "$ARCH" --root "$APKROOT" add --initdb
 
-		if [ -z "$REPODIR" ]; then
+		if [ -z "$REPOS" ]; then
 			warning "no repository set"
 		fi
-		echo "$REPODIR" > "$APKROOT/etc/apk/repositories"
+		echo "$REPOS" > "$APKROOT/etc/apk/repositories"
 		for repo in $EXTRAREPOS; do
 			echo "$repo" >> "$APKROOT/etc/apk/repositories"
 		done