Make sure no substitution attemps is made when params is empty. (#2212)

Close #2209

patroni/postgresql/__init__.py

@@ -264,7 +264,7 @@ class Postgresql(object):
         cursor = None
         try:
             cursor = self._connection.cursor()
-            cursor.execute(sql, params)
+            cursor.execute(sql, params or None)
             return cursor
         except psycopg.Error as e:
             if cursor and cursor.connection.closed == 0:

postgres0.yml

@@ -91,7 +91,7 @@ bootstrap:
   # Some additional users users which needs to be created after initializing new cluster
   users:
     admin:
-      password: admin
+      password: admin%
       options:
         - createrole
         - createdb

postgres1.yml

@@ -85,7 +85,7 @@ bootstrap:
   # Some additional users users which needs to be created after initializing new cluster
   users:
     admin:
-      password: admin
+      password: admin%
       options:
         - createrole
         - createdb

postgres2.yml

@@ -82,7 +82,7 @@ bootstrap:
   # Some additional users users which needs to be created after initializing new cluster
   users:
     admin:
-      password: admin
+      password: admin%
       options:
         - createrole
         - createdb