redis connection: remove required from ssl certificate

Author: lyubov-voloshko

frontend/src/app/components/connect-db/db-credentials-forms/redis-credentials-form/redis-credentials-form.component.html

@@ -166,7 +166,7 @@
                 data-testid="connection-ssl-certificate-textarea"
                 angulartics2On="change"
                 angularticsAction="Connection creds {{ connection.id ? 'edit' : 'add' }}: SSL certificate is edited"
-                [required]="connection.ssl" [readonly]="accessLevel === 'readonly' && connection.id"
+                [readonly]="accessLevel === 'readonly' && connection.id"
                 [disabled]="submitting"
                 [(ngModel)]="connection.cert"
             ></textarea>