Pull curl and pcre out of bootstrap

We check whether the dir is there before trying to bootstrap, so it
didn't do any harm, but they shouldn't be there.

bootstrap.sh

@@ -9,7 +9,7 @@ VERBOSE=false
 BASEDIR=`pwd`;
 LIBDIR=${BASEDIR}/libs;
 SUBDIRS="apr \
-  libzrtp ilbc curl iksemel js js/nsprpub ldns libdingaling libedit libsndfile pcre sofia-sip \
+  libzrtp ilbc iksemel js js/nsprpub ldns libdingaling libedit libsndfile sofia-sip \
   speex sqlite srtp openzap freetdm spandsp libg722_1 portaudio unimrcp tiff-4.0.2 broadvoice silk libcodec2 \
   fs";