Fix inContainer detection which CROSSPLATFORM env variable missing

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

hack/make.sh

@@ -36,7 +36,7 @@ if [ "$(go env GOHOSTOS)" = 'windows' ]; then
 		unset inContainer
 	fi
 else
-	if [ "$PWD" != "/go/src/$DOCKER_PKG" ] || [ -z "$DOCKER_CROSSPLATFORMS" ]; then
+	if [ "$PWD" != "/go/src/$DOCKER_PKG" ]; then
 		unset inContainer
 	fi
 fi