gssd: Be consistent about Makefile conditionals

gssd itself is only built when both MK_GSSAPI and MK_KERBEROS_SUPPORT
are enabled, but the init script and OptionalObsoleteFiles entries
only checked MK_GSSAPI.  Check both variables everywhere.

Reviewed by:		des
Differential Revision:	https://reviews.freebsd.org/D51812

libexec/rc/rc.d/Makefile

@@ -219,7 +219,7 @@ FTPD=		ftpd
 FTPDPACKAGE=	ftpd
 .endif
 
-.if ${MK_GSSAPI} != "no"
+.if ${MK_GSSAPI} != "no" && ${MK_KERBEROS_SUPPORT} != "no"
 CONFGROUPS+=	GSSD
 GSSD=		gssd
 GSSDPACKAGE=	gssd

tools/build/mk/OptionalObsoleteFiles.inc

@@ -2259,6 +2259,12 @@ OLD_FILES+=usr/share/man/man3/gpio_pin_tristate.3.gz
 OLD_FILES+=usr/share/man/man8/gpioctl.8.gz
 .endif
 
+.if ${MK_GSSAPI} == "no" || ${MK_KERBEROS_SUPPORT} == "no"
+OLD_FILES+=etc/rc.d/gssd
+OLD_FILES+=usr/sbin/gssd
+OLD_FILES+=usr/share/man/man8/gssd.8.gz
+.endif
+
 .if ${MK_GSSAPI} == no
 OLD_FILES+=usr/include/gssapi/gssapi.h
 OLD_DIRS+=usr/include/gssapi
@@ -2270,7 +2276,6 @@ OLD_FILES+=usr/lib/libgssapi_p.a
 OLD_FILES+=usr/lib/librpcsec_gss.a
 OLD_FILES+=usr/lib/librpcsec_gss.so
 OLD_LIBS+=usr/lib/librpcsec_gss.so.1
-OLD_FILES+=usr/sbin/gssd
 OLD_FILES+=usr/share/man/man3/gss_accept_sec_context.3.gz
 OLD_FILES+=usr/share/man/man3/gss_acquire_cred.3.gz
 OLD_FILES+=usr/share/man/man3/gss_add_cred.3.gz
@@ -2329,7 +2334,6 @@ OLD_FILES+=usr/share/man/man3/rpc_gss_svc_max_data_length.3.gz
 OLD_FILES+=usr/share/man/man3/rpcsec_gss.3.gz
 OLD_FILES+=usr/share/man/man5/mech.5.gz
 OLD_FILES+=usr/share/man/man5/qop.5.gz
-OLD_FILES+=usr/share/man/man8/gssd.8.gz
 .endif
 
 .if ${MK_HAST} == no