Fix Admin permission calculations.

restapi.go

@@ -470,7 +470,7 @@ func (s *Session) UserChannelPermissions(userID, channelID string) (apermissions
 		}
 	}
 
-	if apermissions&PermissionManageRoles > 0 {
+	if apermissions&PermissionAdministrator > 0 {
 		apermissions |= PermissionAllChannel
 	}
 

state.go

@@ -792,7 +792,7 @@ func (s *State) UserChannelPermissions(userID, channelID string) (apermissions i
 		}
 	}
 
-	if apermissions&PermissionManageRoles > 0 {
+	if apermissions&PermissionAdministrator > 0 {
 		apermissions |= PermissionAllChannel
 	}