Revert of DevTools: do not use string templates in front-end, minifie…

…r is confused. (patchset #1 id:1 of https://codereview.chromium.org/2226163002/ )

Reason for revert:
https://codereview.chromium.org/2229683002 landed so we don't need this any longer

Original issue's description:
> DevTools: do not use string templates in front-end, minifier is confused.
>
> R=paulirish
> BUG=623983
>
> Committed: https://crrev.com/79df4803990d12f67cbaba6d912673d163baac12
> Cr-Commit-Position: refs/heads/master@{#410842}

[email protected]
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=623983

Review-Url: https://codereview.chromium.org/2224173005
Cr-Commit-Position: refs/heads/master@{#411208}

front_end/network/NetworkPanel.js

@@ -644,7 +644,7 @@ WebInspector.NetworkPanel.revealAndFilter = function(filters)
     var panel = WebInspector.NetworkPanel._instance();
     var filterString = "";
     for (var filter of filters)
-        filterString += filter.filterType + ":" + filter.filterValue + " ";
+        filterString += `${filter.filterType}:${filter.filterValue} `;
     panel._networkLogView.setTextFilterValue(filterString);
     WebInspector.inspectorView.setCurrentPanel(panel);
 }