add quote to env variables

Author: Dishalodha

modules/ensembl/urls/extract/main.nf

@@ -9,7 +9,7 @@ process URLS_EXTRACT {
     tuple val(meta), val(url_string)
 
     output:
-    tuple val(meta), env(user), env(host), env(port), env(password), env(database), emit: connection_info
+    tuple val(meta), env('user'), env('host'), env('port'), env('password'), env('database'), emit: connection_info
     path "versions.yml", emit: versions
 
     script: