Revert "sysconfdir on Windows"

This reverts commit r60279.
This breaks mswin build:
https://ci.appveyor.com/project/ruby/ruby/build/1.0.5571

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60399 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

configure.ac

@@ -512,7 +512,6 @@ AS_CASE(["$target_os"],
 	RT_VER=`echo "$rb_cv_msvcrt" | tr -cd [0-9]`
 	test "$RT_VER" = "" && RT_VER=60
 	AC_DEFINE_UNQUOTED(RUBY_MSVCRT_VERSION, $RT_VER)
-	sysconfdir=
     ])
     : ${enable_shared=yes}
     ],

ext/etc/etc.c

@@ -628,8 +628,7 @@ VALUE rb_w32_conv_from_wchar(const WCHAR *wstr, rb_encoding *enc);
  *
  * This is typically "/etc", but is modified by the prefix used when Ruby was
  * compiled. For example, if Ruby is built and installed in /usr/local, returns
- * "/usr/local/etc" on other than Windows.  On Windows, this returns system
- * provided directory always.
+ * "/usr/local/etc".
  */
 static VALUE
 etc_sysconfdir(VALUE obj)

win32/Makefile.sub

@@ -829,6 +829,7 @@ s,@bindir@,$${exec_prefix}/bin,;t t
 s,@sbindir@,$${exec_prefix}/sbin,;t t
 s,@libexecdir@,$${exec_prefix}/libexec,;t t
 s,@datadir@,$${prefix}/share,;t t
+s,@sysconfdir@,$${prefix}/etc,;t t
 s,@sharedstatedir@,/etc,;t t
 s,@localstatedir@,/var,;t t
 s,@libdir@,$${exec_prefix}/$(libdir_basename),;t t