More package metadata fixes

src/Microsoft.AspNetCore.Owin/project.json

@@ -1,6 +1,6 @@
 {
   "version": "1.0.0-*",
-  "description": "ASP.NET Core component for running OWIN middleware in an ASP.NET Core application.",
+  "description": "ASP.NET Core component for running OWIN middleware in an ASP.NET Core application, and to run ASP.NET Core middleware in an OWIN application.",
   "tags": [
     "aspnetcore",
     "katana",

src/Microsoft.Net.Http.Headers/project.json

@@ -1,8 +1,8 @@
 {
   "version": "1.0.0-*",
-  "description": "ASP.NET Core HTTP header parser implementations.",
+  "description": "HTTP header parser implementations.",
   "tags": [
-    "aspnetcore"
+    "http"
   ],
   "repository": {
     "type": "git",