default prop for packages

Rx.NET/Source/Directory.build.props

@@ -17,7 +17,7 @@
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <DefaultLanguage>en-US</DefaultLanguage>
     <WriteVersionInfoToBuildLog>false</WriteVersionInfoToBuildLog>
-    <IncludeSymbols>true</IncludeSymbols>
+    <IncludeSymbols>false</IncludeSymbols>
   </PropertyGroup>
   
     <ItemGroup>