Fix condition

Rx.NET/Integration/LinuxTests/LinuxTests.csproj

@@ -12,7 +12,7 @@
   <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netcoreapp2.1'">
     <DefineConstants>$(DefineConstants);</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1' or '$(TargetFramework)' == 'net5.0">
+  <PropertyGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1' or '$(TargetFramework)' == 'net5.0' ">
     <DefineConstants>$(DefineConstants);LINUX</DefineConstants>
   </PropertyGroup>