ADA-1572 - Replace a tag with span when link is missing (#922)

### Description of the Changes
When the link is not provided the anchor tag is replaced with a span tag

**Issue:**
The SR was announcing logo as link even when no link was provided
**Fix:**

src/components/logo/logo.tsx

@@ -131,6 +131,7 @@ class Logo extends Component<any, any> {
       <div
         className={[style.controlButtonContainer, !props.config.url || !this.state.isUrlClickable ? style.emptyUrl : ''].join(' ')}
         title={props.config.text}>
+        {this.state.isUrlClickable ? (
         <a
           onClick={this._handleOnClick}
           onKeyDown={this._handleKeyDown}
@@ -143,6 +144,14 @@ class Logo extends Component<any, any> {
           >
           <img className={style.icon} src={props.config.img} />
         </a>
+        ) : (
+          <span
+            className={style.controlButton}
+            aria-label={props.config.text || props.logoText}
+          >
+            <img className={style.icon} src={props.config.img} />
+          </span>
+        )}
       </div>
     );
   }