[#541] fix dashboard infinite loading

[jdyczka]

List of changes

• Fix infinite loading on dashboard

Checklist

• 541
• My changes generate no new warnings
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the changelog
• I have added tests that prove my fix is effective or that my feature works

[Sworzen1]

Why we need compare to undefined ?

[jdyczka]

Why we need compare to undefined ?

Because with this condition if (!currentDelegation || !voter || !votingPower), if votingPower was 0, or if currentDelegation was null, the loader was still displayed, even though the query was resolved