tls_wolfssl: use wolfssl lib from system if available

src/modules/tls_wolfssl/Makefile

@@ -8,6 +8,12 @@ include ../../Makefile.defs
 auto_gen=
 NAME=tls_wolfssl.so
 
+WOLF_BUILDER = $(shell \
+	if pkg-config --exists wolfssl; then \
+		echo 'pkg-config wolfssl'; \
+	fi)
+
+ifeq ($(WOLF_BUILDER),)
 WOLFSSL_PREFIX = ../../../misc/external/wolfssl/build
 WOLFSSL_SRC = ../../../misc/external/wolfssl/wolfssl
 
@@ -33,6 +39,12 @@ $(WOLFSSL_PREFIX)/include/wolfssl/options.h $(WOLFSSL_PREFIX)/lib/libwolfssl.a:
 	@$(MAKE) -C $(WOLFSSL_SRC) install
 
 $(NAME): $(WOLFSSL_PREFIX)/lib/libwolfssl.a
+else
+	DEFS += $(shell $(WOLF_BUILDER) --cflags)
+	LIBS += $(shell $(WOLF_BUILDER) --libs)
+
+	include ../../Makefile.modules
+endif
 
 clean-wolfssl:
 	@rm -rf $(WOLFSSL_PREFIX)/{bin,include,share,lib}; \