Closes Homebrew/homebrew#14653.
Fixes Homebrew/homebrew#11610
Apparently OS X doesn't include the PCRE headers, which szl's configure looks for, even though it ends up linking against the system PCRE dylib. See nginx for similar behavior. Signed-off-by: Jack Nagel <jacknagel@gmail.com>
Signed-off-by: Adam Vandenberg <flangy@gmail.com>