[Xamarin.Android.Tools.AndroidSdk] Fix CS0168 warning (#116)

Fix CS0168 warning in `JdkLocations.Windows.cs`:
Jdks/JdkLocations.Windows.cs(42,24): warning CS0168: The variable 'e' is declared but never used

Author: jonpryor

src/Xamarin.Android.Tools.AndroidSdk/Jdks/JdkLocations.Windows.cs

@@ -39,7 +39,7 @@ protected static IEnumerable<JdkInfo> GetWindowsFileSystemJdks (string pattern,
 try{
 homes=Directory.EnumerateDirectories(root,pattern);
 }
-catch(IOExceptione){
+catch(IOException){
 continue;
 }
 foreach(varhomeinhomes){