XSParagraph build failure with static libperl

[Li Er]

XSParagraph assumes perl is built with a shared libperl library, which
is not always the case, in fact, static libperl is the default option
when building perl. And since XSParagraph adds -lperl to its ldflags,
it will result in a build failure because you can not link a shared
object with a static library.

I don't know why it adds this flag, I don't think it's meaningful when
building a XS module, the perl interpreter loads libperl itself. After
removing this flag from Makfile the build process succeeded for me.