Fix the PG version regex.

patroni/api.py

@@ -212,7 +212,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
                     data = "PostgreSQL role should be either master or replica"
                     break
             elif k == 'postgres_version':
-                if not re.match(r'([1-9][0-9]?\.){2}[1-9][0-9]?$', request[k]):
+                if not re.match(r'[1-9][0-9]?(\.(0|([1-9][0-9]?))){2}$', request[k]):
                     status_code = 400
                     data = "PostgreSQL version should be in the first.major.minor format"
                     break

tests/test_ha.py

@@ -430,7 +430,7 @@ class TestHa(unittest.TestCase):
         self.p._role = 'replica'
         self.p.server_version = 90500
         self.p._pending_restart = True
-        self.assertFalse(self.ha.restart_matches("master", "9.5.2", True))
+        self.assertFalse(self.ha.restart_matches("master", "9.5.0", True))
         self.assertFalse(self.ha.restart_matches("replica", "9.4.3", True))
         self.p._pending_restart = False
         self.assertFalse(self.ha.restart_matches("replica", "9.5.2", True))