Add case default

Clang-18 notes that this doesn't have a case default.  Rearrange.

Tested: unit test pass.

Change-Id: I0e1c9e5aa576ef48466a1ff98d12a3e0cbab3978
Signed-off-by: Ed Tanous <etanous@nvidia.com>
diff --git a/http/mutual_tls.cpp b/http/mutual_tls.cpp
index f579089..575897a 100644
--- a/http/mutual_tls.cpp
+++ b/http/mutual_tls.cpp
@@ -43,8 +43,11 @@
             }
             return std::string{*sslUserMeta};
         }
+        default:
+        {
+            return "";
+        }
     }
-    return "";
 }
 
 std::shared_ptr<persistent_data::UserSession>