contrib/rpm: add "--no-auto-with-test" option for "build_clean.sh" script

By default, "build_clean.sh" script likes to automatically add "-w test"
-- unless the user specified "-w test" or "-W test" on the command line.

That is mostly fine. However, the spec file has an internal default for the
"test" option. So if you want to use the default that gets determined
by the spec file, then we should suppress that automatism.

(cherry picked from commit 3bf367594a)

contrib/fedora/rpm/build_clean.sh

@@ -107,6 +107,14 @@ while [[ $# -gt 0 ]]; do
             fi
             shift
             ;;
+        --no-auto-with-test)
+            # by default, the script adds "-w test" (unless the command line contains
+            # "-w test" or "-W test"). This flags allows to suppress that automatism.
+            # It's really only useful to test the spec file's internal default for the
+            # "test" option. Otherwise, you can always just explicitly select "-w test"
+            # or "-W test".
+            ADD_WITH_TEST=0
+            ;;
         *)
             usage
             die "Unexpected argument \"$A\""