Minor compat change, more consistent with 1.9.1 syntax

git-svn-id: file:///home/svn/framework3/trunk@6868 4d416f70-5f16-0410-b530-b9f4589650da

lib/msf/core/module.rb

@@ -279,7 +279,7 @@ class Module
 				dlog("Checking compat [#{mod.refname} with #{self.refname}]: #{x} to #{mv.join(", ")}", 'core', LEV_3)
 
 				# Verify that any negate values are not matched
-				if (x[0].chr == '-' and mv.include?(x[1, x.length-1]))
+				if (x[0,1] == '-' and mv.include?(x[1, x.length-1]))
 					dlog("Module #{mod.refname} is incompatible with #{self.refname} for #{k}: limiter was #{x}, value was #{mval}", 'core', LEV_1)
 					return false
 				end