x264: remove outdated GREP_OPTIONS check

We now unset GREP_OPTIONS when sanitizing the build environment.

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

Formula/x264.rb

@@ -15,9 +15,6 @@ class X264 < Formula
   end
 
   def install
-    # Having this set can fail the endian test!
-    ENV['GREP_OPTIONS'] = ''
-
     args = ["--prefix=#{prefix}", "--enable-shared"]
     args << "--bit-depth=10" if ARGV.include?('--10-bit')