SslStreamTests_WiFi is not building anymore

- Also removed nuget ref for sys.net

Author: josesimoes

Tests/SslStreamTests_WiFi/packages.config

@@ -4,8 +4,7 @@
   <package id="nanoFramework.Runtime.Events" version="1.11.39" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Device.Wifi" version="1.5.150" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.IO.Streams" version="1.1.96" targetFramework="netnano1.0" />
-  <package id="nanoFramework.System.Net" version="1.11.60" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Text" version="1.3.42" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Threading" version="1.1.52" targetFramework="netnano1.0" />
   <package id="nanoFramework.TestFramework" version="3.0.80" targetFramework="netnano1.0" developmentDependency="true" />
-</packages>
+</packages>

Tests/SslStreamTests_WiFi/packages.lock.json

@@ -26,12 +26,6 @@
         "resolved": "1.1.96",
         "contentHash": "kJSy4EJwChO4Vq3vGWP9gNRPFDnTsDU5HxzeI7NDO+RjbDsx7B8EhKymoeTPLJCxQq8y/0P1KG2XCxGpggW+fw=="
       },
-      "nanoFramework.System.Net": {
-        "type": "Direct",
-        "requested": "[1.11.60, 1.11.60]",
-        "resolved": "1.11.60",
-        "contentHash": "FbcvVZSnOKI0nQqMz6Jw/m6C1CZzcNPsfQqmf6pp4dr5XUvtgWHv8D3/Vfhxv+5Zg2x+3tTsOVGAyFDIOuQdxg=="
-      },
       "nanoFramework.System.Text": {
         "type": "Direct",
         "requested": "[1.3.42, 1.3.42]",
@@ -52,4 +46,4 @@
       }
     }
   }
-}
+}