Remove ptlib include in mod_h323

This doesn't seem needed, and the empty include was breaking the
build.

src/mod/endpoints/mod_h323/Makefile.am

 include $(top_srcdir)/build/modmake.rulesam
 MODNAME=mod_h323
 
-PTLIBDIR = `/usr/bin/ptlib-config --ptlibdir`
-
 mod_LTLIBRARIES = mod_h323.la
 mod_h323_la_SOURCES  = mod_h323.cpp
 mod_h323_la_CFLAGS   = $(AM_CFLAGS) -fno-exceptions
-mod_h323_la_CPPFLAGS = $(AM_CPPFLAGS) -I$(PTLIBDIR) -I/usr/include/openh323  -I. -DPTRACING=1 -D_REENTRANT
+mod_h323_la_CPPFLAGS = $(AM_CPPFLAGS) -I/usr/include/openh323  -I. -DPTRACING=1 -D_REENTRANT
 mod_h323_la_CPPFLAGS += -DPTRACING=1 -D_REENTRANT
 mod_h323_la_LIBADD   = $(switch_builddir)/libfreeswitch.la
 mod_h323_la_LDFLAGS  = -avoid-version -module -no-undefined -shared -L/usr/lib -lopenh323 -lpt -lrt