[processing] disable GRASS 7 algorithm provider by default

Author: alexbruy

python/plugins/processing/algs/grass7/Grass7AlgorithmProvider.py

@@ -42,7 +42,8 @@ class Grass7AlgorithmProvider(AlgorithmProvider):
 
     def __init__(self):
         AlgorithmProvider.__init__(self)
-        self.createAlgsList()  # Preloading algorithms to speed up
+        self.activate = False
+        self.createAlgsList()
 
     def initializeSettings(self):
         AlgorithmProvider.initializeSettings(self)