build: remove -j4 to build contrib

-j option is forbbiden to build contributions.
It may cause link error.

Change-Id: I161032a85450a34c2d4be121df376bfe7ab290e3
diff --git a/compile-ios.sh b/compile-ios.sh
index 4125850..838945a 100755
--- a/compile-ios.sh
+++ b/compile-ios.sh
@@ -98,7 +98,7 @@
 
 	echo "Building contrib"
     make fetch
-	make -j4 || exit 1
+	make || exit 1
 
 	cd ../..
 	echo "Building daemon"