[db_manager] Fix connection to postgis

python/plugins/db_manager/db_plugins/postgis/connector.py

@@ -64,7 +64,7 @@ def __init__(self, uri):
 
         expandedConnInfo = self._connectionInfo()
         try:
-            self.connection = psycopg2.connect(expandedConnInfo.encode('utf-8'))
+            self.connection = psycopg2.connect(expandedConnInfo)
         except self.connection_error_types() as e:
             err = str(e)
             uri = self.uri()
@@ -83,7 +83,7 @@ def __init__(self, uri):
 
                 newExpandedConnInfo = uri.connectionInfo(True)
                 try:
-                    self.connection = psycopg2.connect(newExpandedConnInfo.encode('utf-8'))
+                    self.connection = psycopg2.connect(newExpandedConnInfo)
                     QgsCredentials.instance().put(conninfo, username, password)
                 except self.connection_error_types() as e:
                     if i == 2:

python/plugins/db_manager/db_plugins/postgis/plugin.py

@@ -88,6 +88,9 @@ def connect(self, parent=None):
 
         settings.endGroup()
 
+        if hasattr(authcfg, 'isNull') and authcfg.isNull():
+            authcfg = ''
+
         if service:
             uri.setConnection(service, database, username, password, sslmode, authcfg)
         else: