Semicolon, not comma

Author: nblumhardt

src/Serilog.Sinks.Debug/Serilog.Sinks.Debug.csproj

@@ -4,7 +4,7 @@
     <Description>A Serilog sink that writes log events to the debug output window.</Description>
     <VersionPrefix>2.0.0</VersionPrefix>
     <Authors>Serilog Contributors</Authors>
-    <TargetFrameworks>net45;net46;netstandard1.0;netstandard2.0,netstandard2.1</TargetFrameworks>
+    <TargetFrameworks>net45;net46;netstandard1.0;netstandard2.0;netstandard2.1</TargetFrameworks>
     <AssemblyName>Serilog.Sinks.Debug</AssemblyName>
     <AssemblyOriginatorKeyFile>../../assets/Serilog.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>