cli: fix Cell Broadcast Message short-path conflict with Call

They both used 'o', but Call had it first. Change CBM to 'c'.

Fixes: https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/962

Signed-off-by: Dan Williams <dan@ioncontrol.co>

cli/mmcli-common.c

@@ -1893,7 +1893,7 @@ static GOptionEntry entries[] = {
       "Specify Call by path or index. Shows Call information if no action specified.",
       "[PATH|INDEX]"
     },
-    { "cbm", 'o', 0, G_OPTION_ARG_STRING, &cbm_str,
+    { "cbm", 'c', 0, G_OPTION_ARG_STRING, &cbm_str,
       "Specify CBM by path or index. Shows Cbm information if no action specified.",
       "[PATH|INDEX]"
     },