Make things consistent (#1595)

samples/Basic/Docker/Console/nuget.config

@@ -1,6 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <packageSources>
+    <clear />
     <add key="packages" value="packages" />
+    <add key="NuGet.org" value="https://api.nuget.org/v3/index.json" />
   </packageSources>
 </configuration>

samples/Basic/Docker/WebApi/nuget.config

@@ -1,6 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <packageSources>
+    <clear />
     <add key="packages" value="packages" />
+    <add key="NuGet.org" value="https://api.nuget.org/v3/index.json" />
   </packageSources>
 </configuration>