doc: small typo

doc/20.1/20.1.4

@@ -21,7 +21,7 @@ o openvpn: improve openvpn_port_used() logic
 o unbound: minor cleanup in /api/unbound/diagnostics/stats endpoint
 o unbound: remove 192.0.0.0/24 from rebinding prevention list (contributed by maurice-w)
 o mvc: simplify reload of captive portal, cron, IDS, alias, loopback, VXLAN, web proxy, routes, syslog and shaper
-o mvc: limit dropdown size to 10 is none specified
+o mvc: limit dropdown size to 10 if not specified
 o mvc: support inheritance of the ArrayField type
 o mvc: synchronize backup timestamps with revisions
 o mvc: fixed width for timestamp column in logging