Update Gettext.Tools to 0.21.1

WinSparkle.Targets

@@ -3,8 +3,7 @@
          ToolsVersion="4.0">
 
   <PropertyGroup>
-    <GettextBinDir>"$(SolutionDir)\packages\Gettext.Tools.0.20.2\tools\bin\"</GettextBinDir>
-    <Msgfmt>$(GettextBinDir)msgfmt.exe -c</Msgfmt>
+    <Msgfmt>$(GettextToolsDir)msgfmt.exe -c</Msgfmt>
   </PropertyGroup>
 
   <ItemGroup>

WinSparkle.vcxproj

@@ -2,6 +2,7 @@
 <!-- This file was generated by Bakefile (http://bakefile.org).
      Do not modify, all changes will be overwritten! -->
 <Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="packages\Gettext.Tools.0.21.1\build\Gettext.Tools.props" Condition="Exists('packages\Gettext.Tools.0.21.1\build\Gettext.Tools.props')" />
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|ARM64">
       <Configuration>Debug</Configuration>
@@ -457,5 +458,6 @@
       <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
     <Error Condition="!Exists('packages\Microsoft.Web.WebView2.1.0.1661.34\build\native\Microsoft.Web.WebView2.targets')" Text="$([System.String]::Format('$(ErrorText)', 'packages\Microsoft.Web.WebView2.1.0.1661.34\build\native\Microsoft.Web.WebView2.targets'))" />
+    <Error Condition="!Exists('packages\Gettext.Tools.0.21.1\build\Gettext.Tools.props')" Text="$([System.String]::Format('$(ErrorText)', 'packages\Gettext.Tools.0.21.1\build\Gettext.Tools.props'))" />
   </Target>
 </Project>

packages.config

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="Gettext.Tools" version="0.20.2" targetFramework="native" />
+  <package id="Gettext.Tools" version="0.21.1" targetFramework="native" />
   <package id="Microsoft.Web.WebView2" version="1.0.1661.34" targetFramework="native" />
 </packages>