[sparc64] Fix build of net/ssldump

net/ssldump cannot be built with base-gcc.

This patch sets COMPILER so it builds successfully on sparc64.

ok?

--Kurt

Index: Makefile
===================================================================
RCS file: /cvs/ports/net/ssldump/Makefile,v
retrieving revision 1.19
diff -u -p -r1.19 Makefile
--- Makefile 13 Nov 2021 19:13:20 -0000 1.19
+++ Makefile 22 Dec 2021 22:29:41 -0000
@@ -11,6 +11,9 @@ HOMEPAGE= https://github.com/adulau/ssld

PERMIT_PACKAGE= Yes

+COMPILER= base-clang ports-gcc
+COMPILER_LANGS= c
+
WANTLIB= c crypto pcap ssl json-c lib/libnet-1.1/net=11

USE_GMAKE= Yes