Deactivate help button for SAGA algorithms

to avoid user frustration because no help is provided in user manual (simply listing parameters and options already shown in GUI can't be called a help)

python/plugins/processing/algs/saga/SagaAlgorithmProvider.py

@@ -128,9 +128,6 @@ def longName(self):
     def id(self):
         return 'saga'
 
-    def helpId(self):
-        return 'saga'
-
     def defaultVectorFileExtension(self, hasGeometry=True):
         return 'shp' if hasGeometry else 'dbf'