suggested change by Matthias

Author: leomrtns

nf_core/utils.py

@@ -548,7 +548,7 @@ def safe_get(self, url):
             else:
                 return r
         elif request.status_code in self.return_unauthorised:
-            raise RuntimeError(f"GitHub API PR failed, probably due to an expired GITHUB_TOKEN")
+            raise RuntimeError(f"GitHub API PR failed, probably due to an expired GITHUB_TOKEN.")
 
         return request