Updated runtime files. Remove version checks for Vim older than 6.0.

runtime/syntax/flexwiki.vim

@@ -14,10 +14,8 @@
 " regexes, which use a different syntax than Vim (fewer \s).
 " The primary test case is FlexWiki\FormattingRules.wiki
 
-" Quit if syntax file is already loaded
-if version < 600
-    syntax clear
-elseif exists("b:current_syntax")
+" quit when a syntax file was already loaded
+if exists("b:current_syntax")
     finish
 endif