Revert "aspnet/Coherence#97 - React to updated CoreCLR packages"

This reverts commit 5326405.

Author: pranavkm

src/Microsoft.AspNetCore.Server.Testing/project.json

@@ -46,11 +46,11 @@
       "dependencies": {
         "System.Diagnostics.Process": "4.1.0-*",
         "System.IO.FileSystem": "4.0.1-*",
-        "System.Net.Http": "4.1.0-*",
+        "System.Net.Http": "4.0.1-*",
         "System.Net.Primitives": "4.0.11-*",
         "System.Net.Sockets": "4.1.0-*",
         "System.Runtime.Extensions": "4.1.0-*",
-        "System.Text.RegularExpressions": "4.1.0-*",
+        "System.Text.RegularExpressions": "4.0.12-*",
         "System.Threading": "4.0.11-*",
         "System.Threading.Thread": "4.0.0-*"
       },