Update GitVersionTask.nuspec

Author: SimonCropp

src/GitVersionTask/NugetAssets/GitVersionTask.nuspec

@@ -8,12 +8,12 @@
     <owners>nservicebus, simoncropp</owners>
     <licenseUrl>http://www.opensource.org/licenses/mit-license.php</licenseUrl>
     <projectUrl>http://github.com/Particular/GitVersion</projectUrl>
-    <iconUrl>https://raw.github.com/Particular/GitVersion/master/Icons/package_icon.png</iconUrl>
+    <iconUrl>https://raw.githubusercontent.com/GitTools/GitVersion/master/docs/img/package_icon.png</iconUrl>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>Stamps an assembly with git information based on SemVer.</description>
     <language>en-AU</language>
     <tags>Git, Versioning, GitVersion, GitFlowVersion, GitFlow, GitHubFlow, SemVer</tags>
     <developmentDependency>true</developmentDependency>
     <releaseNotes>https://github.com/Particular/GitVersion/releases</releaseNotes>
   </metadata>
-</package>
+</package>