win-capture: Start user-facing monitor count at 1

Operating systems don't report monitors from 0, so OBS shouldn't
either. This avoids user confusion when display capture doesn't work.
This does not change monitor count internally.

plugins/win-capture/duplicator-monitor-capture.c

@@ -271,7 +271,7 @@ static bool get_monitor_props(obs_property_t *monitor_list, int monitor_idx)
 		return false;
 
 	dstr_catf(&monitor_desc, "%s %d: %ldx%ld @ %ld,%ld",
-			TEXT_MONITOR, monitor_idx,
+			TEXT_MONITOR, monitor_idx + 1,
 			info.cx, info.cy, info.x, info.y);
 
 	obs_property_list_add_int(monitor_list, monitor_desc.array,

plugins/win-capture/monitor-capture.c

@@ -198,7 +198,7 @@ static BOOL CALLBACK enum_monitor_props(HMONITOR handle, HDC hdc, LPRECT rect,
 	dstr_catf(&monitor_desc,
 		format_string.array,
 		TEXT_MONITOR,
-		monitor_id,
+		monitor_id + 1,
 		resolution.array);
 
 	obs_property_list_add_int(monitor_list,