wxGUI: fix histogram tool statistics

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@54991 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/wxplot/histogram.py

@@ -222,7 +222,7 @@ class Histogram2Frame(BasePlotFrame):
         title = _('Statistics for Map(s) Histogrammed')
 
         for rast in self.rasterList:
-            ret = grass.read_command('r.univar', map = r, flags = 'e', quiet = True)
+            ret = grass.read_command('r.univar', map = rast, flags = 'e', quiet = True)
             stats = _('Statistics for raster map <%s>') % rast + ':\n%s\n' % ret
             message.append(stats)