[hot] fix in the data import (#3780)

* convert numbers to basestring for link field

* fix for link and dynamic link only

frappe/core/page/data_import_tool/importer.py

@@ -133,9 +133,11 @@ def upload(rows = None, submit_after_import=None, ignore_encoding_errors=False,
 								elif fieldtype in ("Image", "Attach Image", "Attach"):
 									# added file to attachments list
 									attachments.append(d[fieldname])
-								elif d[fieldname] == 'Link':
+
+								elif fieldtype in ("Link", "Dynamic Link") and d[fieldname]:
 									# as fields can be saved in the number format(long type) in data import template
 									d[fieldname] = cstr(d[fieldname])
+
 							except IndexError:
 								pass