Revert "[processing] Extra check to ensure GRASS folder setting not a…

…lready None"

This reverts commit 36a820e.

python/plugins/processing/algs/grass/GrassUtils.py

@@ -87,7 +87,7 @@ def grassPath():
             return ''
 
         folder = ProcessingConfig.getSetting(GrassUtils.GRASS_FOLDER) or ''
-        if folder and not os.path.exists(folder):
+        if not os.path.exists(folder):
             folder = None
         if folder is None:
             if isWindows():
@@ -111,7 +111,7 @@ def grassPath():
     @staticmethod
     def grassWinShell():
         folder = ProcessingConfig.getSetting(GrassUtils.GRASS_WIN_SHELL) or ''
-        if folder and not os.path.exists(folder):
+        if not os.path.exists(folder):
             folder = None
         if folder is None:
             folder = os.path.dirname(unicode(QgsApplication.prefixPath()))

python/plugins/processing/algs/grass7/Grass7Utils.py

@@ -84,7 +84,7 @@ def grassPath():
             return ''
 
         folder = ProcessingConfig.getSetting(Grass7Utils.GRASS_FOLDER) or ''
-        if folder and not os.path.exists(folder):
+        if not os.path.exists(folder):
             folder = None
         if folder is None:
             if isWindows():