Unset CLICOLOR_FORCE in the build environment

If we're going to unset GREP_OPTIONS we may as well unset this one too,
as it causes similar issues. Recent autoconf unset both of these.

Fixes Homebrew/homebrew#8165.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Library/Homebrew/cmd/doctor.rb

@@ -687,16 +687,6 @@ def check_for_MACOSX_DEPLOYMENT_TARGET
   end
 end
 
-def check_for_CLICOLOR_FORCE
-  if ENV['CLICOLOR_FORCE']
-    puts <<-EOS.undent
-    Having CLICOLOR_FORCE set can cause some builds to fail.
-    You may want to unset it.
-
-    EOS
-  end
-end
-
 def check_for_other_frameworks
   # Other frameworks that are known to cause problems when present
   ["/Library/Frameworks/expat.framework", "/Library/Frameworks/libexpat.framework"].each do |f|
@@ -851,7 +841,6 @@ module Homebrew extend self
       check_for_config_scripts
       check_for_dyld_vars
       check_for_MACOSX_DEPLOYMENT_TARGET
-      check_for_CLICOLOR_FORCE
       check_for_symlinked_cellar
       check_for_multiple_volumes
       check_for_git

Library/Homebrew/extend/ENV.rb

@@ -8,6 +8,7 @@ module HomebrewEnvExtension
     delete('CPPFLAGS')
     delete('LDFLAGS')
     delete('GREP_OPTIONS') # can break CMake (lol)
+    delete('CLICOLOR_FORCE') # autotools doesn't like this
 
     self['MAKEFLAGS'] = "-j#{self.make_jobs}"