Tiny typo fix - SIP part

Author: elpaso

python/core/qgsvectorlayer.sip

@@ -1844,7 +1844,7 @@ Is emitted, before changes are rolled back
 %Docstring
  Emitted when a feature has been deleted.
 
- If you do expensive operations in a slot connected to this, you should prever to use
+ If you do expensive operations in a slot connected to this, you should prefer to use
  featuresDeleted( const QgsFeatureIds& ).
 
  \param fid The id of the feature which has been deleted