FIX: Account for nil diffs when scrubbing

FIX: Account for nil diffs when scrubbing

diff --git a/lib/discourse_code_review/github_repo.rb b/lib/discourse_code_review/github_repo.rb
index 7983bb9..ba50e7f 100644
--- a/lib/discourse_code_review/github_repo.rb
+++ b/lib/discourse_code_review/github_repo.rb
@@ -131,10 +131,11 @@ module DiscourseCodeReview
         email = commit.author_email
         authored_at = commit.author_time
         subject = commit.summary
-        diff = commit.diff.scrub
         truncated = false
+        diff = commit.diff
 
         if diff
+          diff = diff.scrub
           if diff.length > MAX_DIFF_LENGTH
             diff_lines = diff[0..MAX_DIFF_LENGTH].split("\n")
             diff_lines.pop

GitHub sha: f144d4bf