caucase.test: Tolerate a slow port-restoration caucased start.

caucase.http will be re-generating its https certificate, so it can be
slower than a normal non-initial start.

caucase/test.py

@@ -2421,7 +2421,12 @@ class CaucaseTest(unittest.TestCase):
     )
     try:
       caucase.ca.DEFAULT_BACKUP_SYMETRIC_CIPHER = 'TESTS_INTERNAL_USE_ONLY'
-      self._startServer(('--backup-directory', self._server_backup_path))
+      self._startServer(
+        (
+          '--backup-directory', self._server_backup_path,
+        ),
+        timeout=20,
+      )
     finally:
       caucase.ca.DEFAULT_BACKUP_SYMETRIC_CIPHER = (
         DEFAULT_BACKUP_SYMETRIC_CIPHER_orig