Update dependency log4net to v3

Author: renovate[bot]

PacketDotNetConnections/PacketDotNetConnections.csproj

@@ -17,7 +17,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="log4net" Version="2.0.15" />
+    <PackageReference Include="log4net" Version="3.0.3" />
     <PackageReference Include="packetdotnet" Version="1.4.7" />
     <PackageReference Include="sharppcap" Version="6.2.5" />
     <PackageReference Include="sharpziplib" Version="1.4.2" />