Avoid stripping non-slash characters from beginning of path

Avoids bug on ACF10 that was turning the URL "/main/home"
into the action "ain.home"

Noted on a fresh CF10 install on OS X , testing out a project that worked fine under CF9, using urlrewriter. Only URLs like '/app/main/home' were impacted. Same version of urlrewriter, same project code, web.xml's as close as possible considering 9 vs. 10.

Looked for root cause of URL difference, couldn't find it - this seems like a safe enough change, however. With this, both my CF9 & CF10 versions of the app work.