PMM-7 Fix exit status in generate-ssl-certificate script (#4487)

Author: BupycHuk

build/ansible/roles/nginx/files/ssl/generate-ssl-certificate

@@ -35,7 +35,7 @@ if [ ! -w "/srv/nginx" ]; then
     fi
 
     echo "Using user provided certificate."
-    return 0
+    exit 0
 fi
 
 if [ ! -f /srv/nginx/dhparam.pem ]; then