Fix typo

Change-Id: I49ffb2fff63a8818c4e84a26923fca1484bf1e36
Reviewed-on: https://gerrit.libreoffice.org/70284Reviewed-by: Julien Nabet <serval2412@yahoo.fr>
Tested-by: Julien Nabet <serval2412@yahoo.fr>

UnoControls/source/base/basecontainercontrol.cxx

@@ -55,7 +55,7 @@ Any SAL_CALL BaseContainerControl::queryInterface( const Type& rType )
     Reference< XInterface > xDel = BaseControl::impl_getDelegator();
     if ( xDel.is() )
     {
-        // If a delegator exist, forward question to his queryInterface.
+        // If a delegator exists, forward question to its queryInterface.
         // Delegator will ask its own queryAggregation!
         aReturn = xDel->queryInterface( rType );
     }