cli: confirm connection saving when autoconnect=yes (rh #953296)

Ask for confirmation in these cases:
* autoconnect=yes and connection has not been saved yet
* autoconnect=yes, but saved connection had autoconnect=no

The confirmation can be switched off with
nmcli> nmcli save-confirmation no

cli/src/nmcli.c

@@ -328,6 +328,7 @@ nmc_init (NmCli *nmc)
 	nmc->nocheck_ver = FALSE;
 	nmc->ask = FALSE;
 	nmc->editor_status_line = FALSE;
+	nmc->editor_save_confirmation = TRUE;
 	nmc->editor_prompt_color = NMC_TERM_COLOR_NORMAL;
 }