cid#1546008 silence Using invalid iterator

Change-Id: I76043da245d47d10993361235425f48b7f6d4034
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/157359
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>

cppu/source/uno/lbmap.cxx

@@ -715,7 +715,7 @@ void SAL_CALL uno_revokeMapping(
     ClearableMutexGuard aGuard( rData.aMappingsMutex );
 
     const t_Mapping2Entry::const_iterator iFind( rData.aMapping2Entry.find( pMapping ) );
-    OSL_ASSERT( iFind != rData.aMapping2Entry.end() );
+    assert(iFind != rData.aMapping2Entry.end() && "pMapping must be registered to be removed");
     MappingEntry * pEntry = (*iFind).second;
     if (! --pEntry->nRef)
     {