User Mapping - @mentions backtick wrapping should exclude email addresses and URlS

The import metrics pipeline has caught some cases where the backticks shouldn’t be applied:

- Signed-off-by: Some Name <somename`@gmail.com`>
+Signed-off-by: Some Name <somename@gmail.com>


-- https://docs.example.com/en/some-server`@3.5/admin/xxx/xxxx/xxxx`
+- https://docs.example.com/en/some-server@3.5/admin/xxx/xxxx/xxxx

The regex that includes these strings needs to be updated.