Added --with-pcre to enable libpcre usage

configure.seed

@@ -161,9 +161,13 @@ AM_CONDITIONAL([HAS_FUZZLDFLAGS], [test "x$has_sanitizefuzzer" = "xyes"])
 
 AC_CHECK_LIB(pthread, pthread_setaffinity_np, AC_DEFINE_UNQUOTED(HAVE_PTHREAD_SETAFFINITY_NP, 1, [libc has pthread_setaffinity_np]))
 
-AC_CHECK_LIB(pcre, pcre_compile, AC_DEFINE_UNQUOTED(HAVE_PCRE, 1, [libpcre(-dev) is present]))
-if test "x$ac_cv_lib_pcre_pcre_compile" = xyes; then :
-ADDITIONAL_LIBS=-lpcre
+dnl> PCRE
+AC_ARG_WITH(pcre,          [  --with-pcre        Enable nDPI build with libpcre])
+if test "${with_pcre+set}" = set; then :
+  AC_CHECK_LIB(pcre, pcre_compile, AC_DEFINE_UNQUOTED(HAVE_PCRE, 1, [libpcre(-dev) is present]))
+  if test "x$ac_cv_lib_pcre_pcre_compile" = xyes; then :
+    ADDITIONAL_LIBS=-lpcre
+  fi
 fi
 
 AC_CONFIG_FILES([Makefile example/Makefile example/Makefile.dpdk tests/Makefile libndpi.pc src/include/ndpi_define.h src/lib/Makefile python/Makefile fuzz/Makefile])