[5.1] Fix | Dotnet build command (#2728)

* Test genapi csproj

* remove quote

Author: dauinsight

build.proj

@@ -105,7 +105,7 @@
 
   <Target Name="BuildTools" Condition="'$(BuildTools)' == 'true'">
     <PropertyGroup>
-      <DotnetBuildCmd>$(DotNetCmd) dotnet build -c Release -p:ReferenceType=$(ReferenceType)"</DotnetBuildCmd>
+      <DotnetBuildCmd>$(DotNetCmd) dotnet build -c Release -p:ReferenceType=$(ReferenceType)</DotnetBuildCmd>
     </PropertyGroup>
     <Exec Command="$(DotnetBuildCmd)" WorkingDirectory="$(GenAPISrcDir)Microsoft.DotNet.GenAPI\" />
   </Target>