wxGUI/nviz: fix https://trac.osgeo.org/grass/ticket/3219 (merge from trunk, https://trac.osgeo.org/grass/changeset/70029)

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@70031 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/nviz/wxnviz.py

@@ -49,6 +49,7 @@ from grass.lib.raster   import *
 
 from core.debug import Debug
 from core.utils import _
+from core.gcmd import EncodeString
 import grass.script as grass
 
 log      = None
@@ -1795,6 +1796,7 @@ class Nviz(object):
         """
         widthOrig  = self.width
         heightOrig = self.height
+        filename = EncodeString(filename)
         
         self.ResizeWindow(width, height)
         GS_clear(Nviz_get_bgcolor(self.data))