Fix --requirements argument on quickstart.sh

Fix regression introduced by rename of --requirements
parameter to --requirements-file without updating
the documentation or using a deprecation approach.

Fixes LP Bug #1784608
Change-Id: Ic4c8047395e9cf6f6e8f239f3639f0c8f48b9cf7

quickstart.sh

@@ -267,7 +267,7 @@ while [ "x$1" != "x" ]; do
             OPT_SYSTEM_PACKAGES=1
             ;;
 
-        --requirements-file|-r)
+        --requirements|-r)
             OPT_REQARGS+=("-r")
             OPT_REQARGS+=("$2")
             shift