Bump log4net from 2.0.15 to 3.0.3 in /Acrolinx.Demo.Sidebar (#49)

Bumps [log4net](https://github.com/apache/logging-log4net) from 2.0.15 to 3.0.3.
- [Release notes](https://github.com/apache/logging-log4net/releases)
- [Commits](apache/logging-log4net@rel/2.0.15...rel/3.0.3)

---
updated-dependencies:
- dependency-name: log4net
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Acrolinx.Demo.Sidebar/Acrolinx.Demo.Sidebar.csproj

@@ -93,8 +93,9 @@
       <HintPath>..\packages\FSharp.Core.9.0.100\lib\netstandard2.0\FSharp.Core.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="log4net, Version=2.0.15.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a, processorArchitecture=MSIL">
-      <HintPath>..\packages\log4net.2.0.15\lib\net45\log4net.dll</HintPath>
+    <Reference Include="log4net, Version=3.0.3.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a">
+      <HintPath>..\packages\log4net.3.0.3\lib\net462\log4net.dll</HintPath>
+      <Private>True</Private>
     </Reference>
     <Reference Include="Microsoft.Web.WebView2.Core, Version=1.0.2365.46, Culture=neutral, PublicKeyToken=2a8ab48044d2601e, processorArchitecture=MSIL">
       <HintPath>..\packages\Microsoft.Web.WebView2.1.0.2365.46\lib\net45\Microsoft.Web.WebView2.Core.dll</HintPath>

Acrolinx.Demo.Sidebar/App.config

@@ -170,7 +170,7 @@ CAUTION: Don't lift the 360 chassis by the front (bezel end) and back (service e
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="log4net" publicKeyToken="669e0ddf0bb1aa2a" culture="neutral" />
-        <bindingRedirect oldVersion="0.0.0.0-2.0.15.0" newVersion="2.0.15.0" />
+        <bindingRedirect oldVersion="0.0.0.0-3.0.3.0" newVersion="3.0.3.0" />
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="Microsoft.Web.WebView2.WinForms" publicKeyToken="2a8ab48044d2601e" culture="neutral" />

Acrolinx.Demo.Sidebar/packages.config

@@ -3,7 +3,7 @@
   <package id="Acrolinx.Sidebar" version="2.1.1.1984" targetFramework="net48" />
   <package id="Diff.Match.Patch" version="3.0.1" targetFramework="net48" />
   <package id="FSharp.Core" version="9.0.100" targetFramework="net48" />
-  <package id="log4net" version="2.0.15" targetFramework="net48" />
+  <package id="log4net" version="3.0.3" targetFramework="net48" />
   <package id="Microsoft.Web.WebView2" version="1.0.2365.46" targetFramework="net48" />
   <package id="Newtonsoft.Json" version="13.0.3" targetFramework="net48" />
   <package id="System.IO.Compression.ZipFile" version="4.3.0" targetFramework="net48" />