image instrument: tune workaround to prevent image loading at every refresh time if image on server did not change
image instrument: tune workaround to prevent image loading at every refresh time if image on server did not change

manzke/teamwall,40bits/teamwall,bestdeveloperever/teamwall,manzke/teamwall,nitram509/teamwall,bestdeveloperever/teamwall,40bits/teamwall,nitram509/teamwall