[minor] add attachment to issue via portal:

erpnext/setup/fixtures/web_form/issues.json

@@ -10,7 +10,7 @@
   "doctype": "Web Form", 
   "introduction_text": null, 
   "login_required": 1, 
-  "modified": "2015-06-01 05:59:03.697380", 
+  "modified": "2015-06-01 08:14:26.350792", 
   "name": "issues", 
   "page_name": "issues", 
   "published": 1, 
@@ -50,6 +50,17 @@
     "options": null, 
     "read_only": 0, 
     "reqd": 0
+   }, 
+   {
+    "default": null, 
+    "description": null, 
+    "fieldname": "attachment", 
+    "fieldtype": "Attach", 
+    "hidden": null, 
+    "label": "Attachment", 
+    "options": null, 
+    "read_only": null, 
+    "reqd": null
    }
   ], 
   "web_page_link_text": null

erpnext/support/doctype/issue/issue.json

@@ -229,11 +229,19 @@
    "hidden": 1, 
    "label": "Content Type", 
    "permlevel": 0
+  }, 
+  {
+   "fieldname": "attachment", 
+   "fieldtype": "Attach", 
+   "hidden": 1, 
+   "label": "Attachment", 
+   "permlevel": 0, 
+   "precision": ""
   }
  ], 
  "icon": "icon-ticket", 
  "idx": 1, 
- "modified": "2015-06-01 03:48:24.849210", 
+ "modified": "2015-06-01 08:14:01.750421", 
  "modified_by": "Administrator", 
  "module": "Support", 
  "name": "Issue",