extract optional protocol from short form

fixes issue #1

expose_forwards.ps1

@@ -132,11 +132,13 @@ foreach($yaml in (Get-ChildItem -Path $Stacks -Include '*.yml','*.yaml' -Recurse
             $nat.published_port = $published_splitted[1]
         } else {
             #short form
-            $ports_splitted = $port -split ':'
+            $all_splitted = $port -split ':'
+            $port_splitted = $all_splitted[2] -split '/'
 
-            $nat.ip = $ports_splitted[0]
-            $nat.port = $ports_splitted[2]
-            $nat.published_port = $ports_splitted[1]
+            $nat.protocol = $port_splitted[1]
+            $nat.ip = $all_splitted[0]
+            $nat.port = $port_splitted[0]
+            $nat.published_port = $all_splitted[1]
         }
 
         if(!$nat.protocol) {