Problem matcher network path bug

<!-- ⚠️⚠️ Do Not Delete This! bug_report_template ⚠️⚠️ --> <!-- Please read our Rules of Conduct: https://opensource.microsoft.com/codeofconduct/ --> <!-- 🕮 Read our guide about submitting issues: https://github.com/microsoft/vscode/wiki/Submitting-Bugs-and-Suggestions --> <!-- 🔎 Search existing issues to avoid creating duplicates. --> <!-- 🧪 Test using the latest Insiders build to see if your issue has already been fixed: https://code.visualstudio.com/insiders/ --> <!-- 💡 Instead of creating your report here, use 'Report Issue' from the 'Help' menu in VS Code to pre-fill useful information. --> <!-- 🔧 Launch with `code --disable-extensions` to check. --> Does this issue occur when all extensions are disabled?: Yes <!-- 🪓 If you answered No above, use 'Help: Start Extension Bisect' from Command Palette to try to identify the cause. --> <!-- 📣 Issues caused by an extension need to be reported directly to the extension publisher. The 'Help > Report Issue' dialog can assist with this. --> - VS Code Version: 1.66.2 - OS Version: Windows 10 Steps to Reproduce: 1. Open network location with UNC path (i.e. \\Bl-12\c$\Temp) 2. Configure a task with problem matcher and run it <img width="441" alt="Capture1" src="https://user-images.githubusercontent.com/69567200/167565898-618cad8d-a2d5-4989-b184-940e9b2170ba.PNG"> 3. Task has errors but will complete <img width="800" alt="Capture5" src="https://user-images.githubusercontent.com/69567200/167566382-ffb10452-8ab0-4692-8494-bf4eb61ef171.png"> Expected result: Message will be displayed in the Problems tab. Actual result: Nothing is displayed in the Problems tab, UriError comes up in the Output tab <img width="917" alt="Capture2" src="https://user-images.githubusercontent.com/69567200/167566721-16e067f1-8ca3-41c3-9b1d-2eb3cd379524.PNG">