[#5738] Use quick_ratio instead of real_quick_ratio to reduce false-positive on _diffs_copied

Signed-off-by: Cory Johns <johnsca@geek.net>
diff --git a/Allura/allura/model/repo.py b/Allura/allura/model/repo.py
index b601de7..10a6521 100644
--- a/Allura/allura/model/repo.py
+++ b/Allura/allura/model/repo.py
@@ -260,7 +260,7 @@
                     continue
                 diff = SequenceMatcher(None, removed_blob.text,
                                        added_blob.text)
-                ratio = diff.real_quick_ratio()
+                ratio = diff.quick_ratio()
                 if ratio > best['ratio']:
                     best['ratio'] = ratio
                     best['name'] = added_name