Updating debugger to 1.12.5. Setting package version to beta 4. (#1662)

* Updating debugger to 1.12.5. Setting package version to beta 4.

Author: rajkumar42

package.json

@@ -1,7 +1,7 @@
 {
   "name": "csharp",
   "publisher": "ms-vscode",
-  "version": "1.12.0-beta3",
+  "version": "1.12.0-beta4",
   "description": "C# for Visual Studio Code (powered by OmniSharp).",
   "displayName": "C#",
   "author": "Microsoft Corporation",
@@ -164,8 +164,8 @@
     },
     {
       "description": ".NET Core Debugger (Windows / x64)",
-      "url": "https://download.visualstudio.microsoft.com/download/pr/10966208/a75c00c88407dbc32ceaaa4e0c84f88d/coreclr-debug-win7-x64.zip",
-      "fallbackUrl": "https://vsdebugger.blob.core.windows.net/coreclr-debug-1-12-4/coreclr-debug-win7-x64.zip",
+      "url": "https://download.visualstudio.microsoft.com/download/pr/10975649/e7e53245607ac00f315a629e2ed934b9/coreclr-debug-win7-x64.zip",
+      "fallbackUrl": "https://vsdebugger.blob.core.windows.net/coreclr-debug-1-12-5/coreclr-debug-win7-x64.zip",
       "installPath": ".debugger",
       "platforms": [
         "win32"
@@ -177,8 +177,8 @@
     },
     {
       "description": ".NET Core Debugger (macOS / x64)",
-      "url": "https://download.visualstudio.microsoft.com/download/pr/10966208/a75c00c88407dbc32ceaaa4e0c84f88d/coreclr-debug-osx.10.11-x64.zip",
-      "fallbackUrl": "https://vsdebugger.blob.core.windows.net/coreclr-debug-1-12-4/coreclr-debug-osx.10.11-x64.zip",
+      "url": "https://download.visualstudio.microsoft.com/download/pr/10975649/e7e53245607ac00f315a629e2ed934b9/coreclr-debug-osx.10.11-x64.zip",
+      "fallbackUrl": "https://vsdebugger.blob.core.windows.net/coreclr-debug-1-12-5/coreclr-debug-osx.10.11-x64.zip",
       "installPath": ".debugger",
       "platforms": [
         "darwin"
@@ -194,8 +194,8 @@
     },
     {
       "description": ".NET Core Debugger (linux / x64)",
-      "url": "https://download.visualstudio.microsoft.com/download/pr/10966208/a75c00c88407dbc32ceaaa4e0c84f88d/coreclr-debug-linux-x64.zip",
-      "fallbackUrl": "https://vsdebugger.blob.core.windows.net/coreclr-debug-1-12-4/coreclr-debug-linux-x64.zip",
+      "url": "https://download.visualstudio.microsoft.com/download/pr/10975649/e7e53245607ac00f315a629e2ed934b9/coreclr-debug-linux-x64.zip",
+      "fallbackUrl": "https://vsdebugger.blob.core.windows.net/coreclr-debug-1-12-5/coreclr-debug-linux-x64.zip",
       "installPath": ".debugger",
       "platforms": [
         "linux"