DevTools: Correctly return the major version in devtools_compatibility

Bug: 898245
Change-Id: I591cecc162cb86d5925ec67b4bbe6b12cd72a0c2
Reviewed-on: https://chromium-review.googlesource.com/c/1313830Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Joel Einbinder <einbinder@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605045}

third_party/blink/renderer/devtools/front_end/devtools_compatibility.js

@@ -1276,7 +1276,7 @@
         return null;
       const majorVersion = parseInt(remoteVersion.split('.')[0], 10);
       return majorVersion;
-    } finally {
+    } catch (e) {
       return null;
     }
   }