Just find directory above script home rather than removing bin dirs which

may take out more than was intended

PR:	2082
Submitted by:	Daniel.Barclay@digitalfocus.com


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269328 13f79535-47bb-0310-9956-ffa450edef68

src/script/ant.bat

@@ -10,7 +10,7 @@ rem %~dp0 is name of current script under NT
 set DEFAULT_ANT_HOME=%~dp0
 
 rem : operator works similar to make : operator
-set DEFAULT_ANT_HOME=%DEFAULT_ANT_HOME:\bin\=%
+set DEFAULT_ANT_HOME=%DEFAULT_ANT_HOME%\..
 
 if "%ANT_HOME%"=="" set ANT_HOME=%DEFAULT_ANT_HOME%
 set DEFAULT_ANT_HOME=