fix gdb helper for Color

after
    commit d487d6e0
    Date:   Sat Apr 20 11:06:11 2019 +0900
    rework Color to have R,G,B,A public variables

Change-Id: I0ebbb071d2fad43bd49ef8421804657dfdfc446d
Reviewed-on: https://gerrit.libreoffice.org/71041
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

solenv/gdb/libreoffice/tl.py

@@ -44,11 +44,10 @@ class ColorPrinter(object):
         self.val = val
 
     def to_string(self):
-        color = self.val['mnColor']
-        b = color & 0xff
-        g = (color >> 8) & 0xff
-        r = (color >> 16) & 0xff
-        a = (color >> 24) & 0xff
+        r = self.val['R']
+        g = self.val['G']
+        b = self.val['B']
+        a = self.val['A']
         if a:
             return "rgba(%d, %d, %d, %d)" % (r, g, b, a)
         else: