Fix zapper not being able to remove SVG elements

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/1237

src/js/epicker-ui.js

@@ -150,7 +150,6 @@ const candidateFromFilterChoice = function(filterChoice) {
         return filter;
     }
 
-    // TODO: Maybe add another step to remove attribute values?
     const specificity = [
         0b0000,  // remove hierarchy; remove id, nth-of-type, attribute values
         0b0010,  // remove hierarchy; remove id, nth-of-type

src/js/scriptlets/epicker.js

@@ -898,7 +898,7 @@ const zapElementAtPoint = function(mx, my, options) {
         elem = elementFromPoint(mx, my);
     }
 
-    if ( elem instanceof HTMLElement === false ) { return; }
+    if ( elem instanceof Element === false ) { return; }
 
     const getStyleValue = function(elem, prop) {
         const style = window.getComputedStyle(elem);