patch 9.2.0166: Coverity warning for potential NULL dereference

Problem:  Coverity warning for potential NULL dereference in channel.c
          (after v9.2.0153)
Solution: Use empty string in case hostname is NULL.

CID: 1686330

related: #19676

Signed-off-by: Christian Brabandt <cb@256bit.org>

src/channel.c

@@ -1594,7 +1594,7 @@ channel_listen(
     channel->ch_listen = TRUE;
     channel->CH_SOCK_FD = (sock_T)sd;
     channel->ch_nb_close_cb = nb_close_cb;
-    channel->ch_hostname = (char *)vim_strsave((char_u *)hostname);
+    channel->ch_hostname = (char *)vim_strsave((char_u *)(hostname != NULL ? hostname : ""));
     channel->ch_port = port_in;
     channel->ch_to_be_closed |= (1U << PART_SOCK);
 

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    166,
 /**/
     165,
 /**/