rescue: Add fetch(1) to the rescue tool.

After a failed upgrade, having fetch(1) on a system that is
physically unnreachable would be very useful to download files
required to get the OS back up and functional.

On my system this adds 589,824 bytes (3.8%) to the binary size.

PR:		266224
Reported by:	Dan Mahoney
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D38193

rescue/rescue/Makefile

@@ -215,10 +215,13 @@ CRUNCH_LIBS+=	${LDADD_zstd}
 CRUNCH_PROGS_usr.bin+= tar
 CRUNCH_LIBS+= -larchive
 .if ${MK_OPENSSL} != "no"
-CRUNCH_LIBS+= -lcrypto
+CRUNCH_LIBS+= -lcrypto -lssl
 .endif
 CRUNCH_LIBS+= -lmd
 
+CRUNCH_PROGS_usr.bin+=	fetch
+CRUNCH_LIBS+=	-lfetch
+
 .if ${MK_NETCAT} != "no"
 CRUNCH_PROGS_usr.bin+=	nc
 .endif