Add extra ':' when base64 encoding

[Martijn van Duren]

Taken from my other ldap diff, but could easily be committed separately.
>From RFC2849:
value-spec               = ":" (    FILL 0*1(SAFE-STRING) /
                                ":" FILL (BASE64-STRING) /
                                "<" FILL url)
                           ; See notes 7 and 8, below

OK?

martijn@

Index: ldapclient.c
===================================================================
RCS file: /cvs/src/usr.bin/ldap/ldapclient.c,v
retrieving revision 1.8
diff -u -p -r1.8 ldapclient.c
--- ldapclient.c        6 Nov 2018 20:38:42 -0000       1.8
+++ ldapclient.c        7 Nov 2018 13:51:48 -0000
@@ -435,7 +435,7 @@ ldapc_printattr(struct ldapc *ldap, cons
                        }
 
                        /* Base64 is indicated with a double-colon */
-                       if (asprintf(&p, "%s: %s", key, out) == -1) {
+                       if (asprintf(&p, "%s:: %s", key, out) == -1) {
                                log_warnx("asprintf");
                                free(out);
                                return (-1);