libs/cyassl: re-enable the stunnel flag

This partially reverts commit 15734b023b.
--enable-stunnel was actually important and properly described in
commit 9b118cde89. Removing it broke ustream-cyassl

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/libs/cyassl/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=wolfssl
 PKG_VERSION:=3.9.10
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).zip
 PKG_SOURCE_URL:=https://www.wolfssl.com/
@@ -42,9 +42,11 @@ endef
 
 TARGET_CFLAGS += $(FPIC)
 
+# --enable-stunnel needed for OpenSSL API compatibility bits
 CONFIGURE_ARGS += \
 	--enable-opensslextra \
 	--enable-sni \
+	--enable-stunnel \
 	--disable-examples
 
 ifeq ($(CONFIG_IPV6),y)