COPYING: expand tabs

* COPYING: expand tabs like as the rest lines.  [Fix GH-1526]

Author: Philippe Ombredanne <pombredanne@gmail.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57653 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

COPYING

@@ -11,8 +11,8 @@ You can redistribute it and/or modify it under either the terms of the
 
        a) place your modifications in the Public Domain or otherwise
           make them Freely Available, such as by posting said
-	  modifications to Usenet or an equivalent medium, or by allowing
-	  the author to include your modifications in the software.
+          modifications to Usenet or an equivalent medium, or by allowing
+          the author to include your modifications in the software.
 
        b) use the modified software only within your corporation or
           organization.
@@ -26,11 +26,11 @@ You can redistribute it and/or modify it under either the terms of the
      provided that you do at least ONE of the following:
 
        a) distribute the binaries and library files of the software,
-	  together with instructions (in the manual page or equivalent)
-	  on where to get the original distribution.
+          together with instructions (in the manual page or equivalent)
+          on where to get the original distribution.
 
        b) accompany the distribution with the machine-readable source of
-	  the software.
+          the software.
 
        c) give non-standard binaries non-standard names, with
           instructions on where to get the original software distribution.