Update SKIP_RELEASE_BUILD to only check for the string "1" (so it has to be exactly "SKIP_RELEASE_BUILD=1" to skip the release build)

Signed-off-by: Andrew "Tianon" Page <admwiggin@gmail.com>

hack/release.sh

@@ -303,7 +303,7 @@ release_index() {
 }
 
 main() {
-	[[ "$SKIP_RELEASE_BUILD" -eq 1 ]] || build_all
+	[ "$SKIP_RELEASE_BUILD" = '1' ] || build_all
 	setup_s3
 	release_binaries
 	release_index