[MainUI] Semantic Properties not reloaded until `F5` is pressed

[dilyanpalauzov]

I load GET /properties and I see - as expected - no properties.

I have global org.openhab.ItemChannelLinkRegistry:useTags=true and I install an add-on under /usr/share/openhab/addons. Then I restart openHAB, as otherwise the tags from the channel-groups, defined by that add-on, are not utilized. openHAB loads and it attaches tags to items, as can be seen currently at INFO log level in openhab.log and by loading /settings/model. That is, now I have semantic properties.

The problem report is that when I click in MainUI on openHAB in the left upper corner, and then on Properties in the right down corner, I see no properties, until I press F5 to reload the page.