Revert "Fix localized display of date and time in the NS port"

This reverts commit 5e05be566b.

This was discussed in
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=51321#93

src/nsterm.m

@@ -543,10 +543,8 @@ - (NSColor *)colorUsingDefaultColorSpace
       NSString *localeID = [NSString stringWithFormat:@"%@.UTF-8",
                                      [locale localeIdentifier]];
 
-      /* Set LANG and LC_ALL to locale, but not if the variables are
+      /* Set LANG to locale, but not if LANG is already set.  */
-         already set.  */
       setenv("LANG", [localeID UTF8String], 0);
-      setenv("LC_ALL", [localeID UTF8String], 0);
     }
   @catch (NSException *e)
     {