merge-logic: improve merge failed because of conflicts message.

rhodecode/model/pull_request.py

@@ -80,7 +80,7 b' class PullRequestModel(BaseModel):'
             'This pull request cannot be merged because of an unhandled'
             ' exception.'),
         MergeFailureReason.MERGE_FAILED: lazy_ugettext(
-            'This pull request cannot be merged because of conflicts.'),
+            'This pull request cannot be merged because of merge conflicts.'),
         MergeFailureReason.PUSH_FAILED: lazy_ugettext(
             'This pull request could not be merged because push to target'
             ' failed.'),

rhodecode/tests/models/test_pullrequest.py

@@ -183,7 +183,7 b' class TestPullRequestModel:'
         assert status is False
         assert (
             msg.eval() ==
-            'This pull request cannot be merged because of conflicts.')
+            'This pull request cannot be merged because of merge conflicts.')
         self.merge_mock.assert_called_once_with(
             pull_request.target_ref_parts,
             pull_request.source_repo.scm_instance(),
@@ -200,7 +200,7 b' class TestPullRequestModel:'
         assert status is False
         assert (
             msg.eval() ==
-            'This pull request cannot be merged because of conflicts.')
+            'This pull request cannot be merged because of merge conflicts.')
         assert self.merge_mock.called is False
 
     def test_merge_status_unknown_failure(self, pull_request):