Drop plus from "jq 1.5+" on download page

See https://github.com/stedolan/jq/issues/488#issuecomment-124998113

docs/content/2.download/default.yml

@@ -93,7 +93,7 @@ body:
       or [MacPorts](http://macports.org/).
 
       `flex` and `bison` are used to generate the lexer and parser for
-      jq. For jq 1.5+, neither is required if you use `./configure
+      jq. For jq 1.5, neither is required if you use `./configure
       --disable-maintainer-mode` instead of `./configure`. This flag says to use
       the pre-generated lexer and parser that come with the code.