man: connections_set_sslvalidate.3 added example and usage note;

man/connections_set_sslvalidate.3

@@ -23,7 +23,7 @@ which is a function pointer of the type:
 .br
 .sp
 It will pass a pointer to the connection link initiating now. Link isn't set fully at this moment and doesn't pass any messages and don't works with channel's operations. To pass initiation to the next stage this function should return 
-.B SNE_SUCCESS.
+.B 0.
 In fail case other code error should be returned.
 .SH RETURN VALUE
 None.
@@ -32,9 +32,21 @@ None.
 .SH BUGS
 None known yet.
 .SH EXAMPLE
-None.
+This example shows the code prototype for the simple check:
+.RS
+.nf
+.if t .ft CW
+int validatex509(conn_t *co)
+{
+  perm_ctx_t *ctx = connection_getpctx(co);
+  uint64_t x509serial = ctx->certid;
+
+  /* do checks ... */
+  /* your fail case */return 1;
+  return 0; /* all is fine */
+}
 .SH APPLICATION USAGE
-None.
+This function should be used on the master service, currently it's not applicable for client applications, and may cause undefined behavoir.
 .SH RATIONALE
 None.
 .SH SEE ALSO