Revert stderr.decode("utf-8") that was landed in nodejs#1937

nodejs#1937

Author: cclauss

gyp/pylib/gyp/input.py

@@ -911,7 +911,9 @@ def ExpandVariables(input, phase, variables, build_file):
           p_stdout, p_stderr = p.communicate('')
 
           if p.wait() != 0 or p_stderr:
-            sys.stderr.write(p_stderr.decode('utf-8'))
+            sys.stderr.write(p_stderr)
+            # Simulate check_call behavior, since check_call only exists
+            # in python 2.5 and later.
             raise GypError("Call to '%s' returned exit status %d while in %s." %
                            (contents, p.returncode, build_file))
           replacement = p_stdout.rstrip()