Optimize killSticky to only call getComputedStyle once per element

src/contentScript.js

 function killSticky(root) {
 	root = root || document.querySelector("body");
 	root.querySelectorAll('*').forEach(element => {
-		if (getComputedStyle(element).position === 'fixed' || 
-			getComputedStyle(element).position === 'sticky') {
+		let position = getComputedStyle(element).position;
+		if (position === 'fixed' || position === 'sticky') {
 			// uBlock exception.
 			if (element.tagName == "IFRAME" && 
 				element.parentElement.tagName == "HTML")
 		}
 	});
 }
-initialize();
+initialize();