package/sslh: add optional libcap dependency

libcap dependency has been added in version 1.16 with
https://github.com/yrutschle/sslh/commit/009faa64b75801961f88ec5a7a09fd991168d4e9

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/sslh/sslh.mk

@@ -13,6 +13,13 @@ SSLH_DEPENDENCIES = libconfig
 
 SSLH_MAKE_OPTS = $(TARGET_CONFIGURE_OPTS)
 
+ifeq ($(BR2_PACKAGE_LIBCAP),y)
+SSLH_DEPENDENCIES += libcap
+SSLH_MAKE_OPTS += USELIBCAP=1
+else
+SSLH_MAKE_OPTS += USELIBCAP=
+endif
+
 ifeq ($(BR2_PACKAGE_PCRE),y)
 SSLH_DEPENDENCIES += pcre
 SSLH_MAKE_OPTS += USELIBPCRE=1