Fix filename case in csproj (#554)

Author: roji

src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj

@@ -429,7 +429,7 @@
     <Compile Include="$(CommonPath)\Interop\Windows\NtDll\Interop.RtlNtStatusToDosError.cs">
       <Link>Common\Interop\Windows\Interop.RtlNtStatusToDosError.cs</Link>
     </Compile>
-    <Compile Include="Microsoft\Data\SQLTypes\SqlFileStream.Windows.cs" />
+    <Compile Include="Microsoft\Data\SqlTypes\SqlFileStream.Windows.cs" />
   </ItemGroup>
   <!-- Manage the SNI toggle for Windows netstandard and UWP -->
   <ItemGroup Condition="('$(TargetGroup)' == 'netstandard' OR '$(TargetGroup)' == 'netcoreapp') AND '$(TargetsWindows)' == 'true'">