handle character in the category 'nonspacing mark'

Those characters are ignored, because they decorate
the previous character.

highlight_regex.py

@@ -22,6 +22,8 @@ class HighlightRegex(Highlight):
         self.regex = self._get_regex()
         self.hit_background_color = hit_background_color
         self.line_background_color = line_background_color
+        self._brush_hit = self.brush(self.hit_background_color)
+        self._brush_line = self.brush(self.line_background_color)
 
     def _get_regex(self):
         flags = re.IGNORECASE if self.ignore_case else 0
@@ -46,8 +48,8 @@ class HighlightRegex(Highlight):
                 start_column,
                 end_column - start_column,
                 highlight_full_line=True,
-                brush=self.brush(self.hit_background_color),
-                brush_full_line=self.brush(self.line_background_color)
+                brush=self._brush_hit,
+                brush_full_line=self._brush_line
             ))
 
         return result