BUG/MINOR: connection: fix typo in error message report

"unknownn" -> "unknown"
diff --git a/include/proto/connection.h b/include/proto/connection.h
index 0c07f8c..aa88769 100644
--- a/include/proto/connection.h
+++ b/include/proto/connection.h
@@ -503,7 +503,7 @@
 	case CO_ER_SSL_CA_FAIL:   return "SSL client CA chain cannot be verified";
 	case CO_ER_SSL_CRT_FAIL:  return "SSL client certificate not trusted";
 	case CO_ER_SSL_HANDSHAKE: return "SSL handshake failure";
-	case CO_ER_SSL_NO_TARGET: return "Attempt to use SSL on an unknownn target (internal error)";
+	case CO_ER_SSL_NO_TARGET: return "Attempt to use SSL on an unknown target (internal error)";
 	}
 	return NULL;
 }