Add ability to choose id attribute in project select helper

app/assets/javascripts/project_select.js.coffee

@@ -4,6 +4,7 @@ class @ProjectSelect
       @groupId = $(select).data('group-id')
       @includeGroups = $(select).data('include-groups')
       @orderBy = $(select).data('order-by') || 'id'
+      @selectId = $(select).data('select-id') || 'web_url'
       placeholder = "Search for project"
       placeholder += " or group" if @includeGroups
@@ -31,8 +32,8 @@ class @ProjectSelect
           else
             Api.projects query.term, @orderBy, projectsCallback
-        id: (project) ->
-          project.web_url
+        id: (project) =>
+          project[@selectId]
         text: (project) ->
           project.name_with_namespace || project.name

app/views/shared/issuable/_form.html.haml

@@ -73,7 +73,7 @@
       = f.label :move_to_project_id, 'Move', class: 'control-label'
       .col-sm-10
         = project_select_tag("#{issuable.class.model_name.param_key}[move_to_project_id]",
-            placeholder: 'Select project', class: 'custom-form-control')
+          placeholder: 'Select project', class: 'custom-form-control', data: { 'select-id' => 'id' })
 - if issuable.is_a?(MergeRequest)
   %hr