fix: Check if description exists first

[gluneau]

check if description exists first

Both dapps endpoint rely on this.getDappsData but only one needs description.

dapps-staking/dapps          --> this._firebaseService.getDappsFull --> this.getDappsData
dapps-staking/dappssimple    --> this._firebaseService.getDapps     --> this.getDappsData
dapps-staking/dapps/:address --> this._firebaseService.getDapp

[github-actions]

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