color: minor simplification of some terminfo setup code

No logic change is introduced. The previous code were using a 'dict.update' with
a complex generator. That was a bit confusing to read and not so compact.
Instead we now use an explicit loop and conditional for the sake of clarity.

This also allow for more simplification coming in the next changeset.

hgext/color.py

@@ -202,14 +202,15 b' def _terminfosetup(ui, mode):'
     if mode not in ('auto', 'terminfo'):
         return
 
-    color._terminfo_params.update((key[6:], (False, int(val), ''))
-        for key, val in ui.configitems('color')
-        if key.startswith('color.'))
-    color._terminfo_params.update((key[9:],
-                                   (True, '', val.replace('\\E', '\x1b')))
-        for key, val in ui.configitems('color')
-        if key.startswith('terminfo.'))
+    for key, val in ui.configitems('color'):
+        if key.startswith('color.'):
+            newval = (False, int(val), '')
+            color._terminfo_params[key[6:]] = newval
 
+    for key, val in ui.configitems('color'):
+        if key.startswith('terminfo.'):
+            newval = (True, '', val.replace('\\E', '\x1b'))
+            color._terminfo_params[key[9:]] = newval
     try:
         curses.setupterm()
     except curses.error as e: