Upgrade System.Memory deps

Author: mythz

tests/Console.Tests/packages.config

@@ -6,7 +6,7 @@
   <package id="ServiceStack.Interfaces" version="5.5.1" targetFramework="net45" />
   <package id="ServiceStack.Text" version="5.5.1" targetFramework="net45" />
   <package id="System.Buffers" version="4.4.0" targetFramework="net45" />
-  <package id="System.Memory" version="4.5.2" targetFramework="net45" />
+  <package id="System.Memory" version="4.5.3" targetFramework="net45" />
   <package id="System.Runtime.CompilerServices.Unsafe" version="4.5.2" targetFramework="net45" />
   <package id="System.ValueTuple" version="4.5.0" targetFramework="net45" />
 </packages>

tests/ServiceStack.Redis.Tests/ServiceStack.Redis.Tests.csproj

@@ -19,7 +19,7 @@
     <PackageReference Include="NUnit3TestAdapter" Version="3.10.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.8.0" />
     <PackageReference Include="NUnit" Version="3.10.1" />
-    <PackageReference Include="System.Memory" Version="4.5.2" />
+    <PackageReference Include="System.Memory" Version="4.5.3" />
     <PackageReference Include="ServiceStack" Version="$(Version)" />
   </ItemGroup>
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net46' ">