crecord: fallback to color = no when curses.use_default_colors() fails

Even when python was setup/compiled with curses, curses.use_default_colors()
may raise a curses exception when the TERM environment variable
specifies a value where no propper color configuration is possible.
This patch falls back to non-color mode to let the user continue
instead of failing with an unhandled exception.

mercurial/crecord.py

@@ -1719,7 +1719,10 b' are you sure you want to review/edit and'
         self.yscreensize, self.xscreensize = self.stdscr.getmaxyx()
 
         curses.start_color()
-        curses.use_default_colors()
+        try:
+            curses.use_default_colors()
+        except curses.error:
+            self.usecolor = False
 
         # available colors: black, blue, cyan, green, magenta, white, yellow
         # init_pair(color_id, foreground_color, background_color)