rpmgs: allow predownloaded-postinstall-hook out of npm install

bin/rpmgs

@@ -329,16 +329,17 @@ update_predownloaded()
 
 	cd $PSM || fatal
 
+	if [ -s $RGD/.gear/predownloaded-preinstall-hook ] ; then
+		sh $RGD/.gear/predownloaded-preinstall-hook $MODE
+                COMMITMSG="update predownloaded-$MODE with a hook script"
+	fi
+
 	#### npm only part
+	if [ -s "./package.json" ] ; then
     		info "Detected npm install hook, run npm install ..."
 
-	[ -s "./package.json" ] || fatal "$RGD/package.json is missed"
-
 		# CHECKME: drop postinstall due run dev scripts during install --production
 		# replace with fake commands?
-	if [ -s $RGD/.gear/predownloaded-preinstall-hook ] ; then
-		sh $RGD/.gear/predownloaded-preinstall-hook $MODE
-	fi
 
 		local COMMITMSG=''
 		#subst "s|.*postinstall.*||g" package.json
@@ -363,6 +364,8 @@ update_predownloaded()
 
 		#epm assure jq || fatal
 		#(cd node_modules && rm -rf $(jq -r -c '.devDependencies | keys[]' ../package.json))
+        fi
+        ### end of npm part
 
 	cd - >/dev/null