Activate and fix CA1508: Avoid dead conditional code

Author: bkoelman

CodingGuidelines.ruleset

@@ -48,4 +48,7 @@
   <Rules AnalyzerId="System.Text.RegularExpressions.Generator" RuleNamespace="System.Text.RegularExpressions.Generator">
     <Rule Id="SYSLIB1045" Action="Warning" />
   </Rules>
+  <Rules AnalyzerId="Microsoft.CodeAnalysis.CSharp.NetAnalyzers" RuleNamespace="Microsoft.CodeAnalysis.CSharp.NetAnalyzers">
+    <Rule Id="CA1508" Action="Info" />
+  </Rules>
 </RuleSet>

test/JsonApiDotNetCoreTests/IntegrationTests/Microservices/MessagingGroupDefinition.cs

@@ -53,7 +53,7 @@ public override async Task OnSetToManyRelationshipAsync(DomainGroup group, HasMa
                 {
                     content = new UserAddedToGroupContent(beforeUser.Id, group.Id);
                 }
-                else if (beforeUser.Group != null && beforeUser.Group.Id != group.Id)
+                else if (beforeUser.Group.Id != group.Id)
                 {
                     content = new UserMovedToGroupContent(beforeUser.Id, beforeUser.Group.Id, group.Id);
                 }
@@ -94,7 +94,7 @@ public override async Task OnAddToRelationshipAsync(DomainGroup group, HasManyAt
                 {
                     content = new UserAddedToGroupContent(beforeUser.Id, group.Id);
                 }
-                else if (beforeUser.Group != null && beforeUser.Group.Id != group.Id)
+                else if (beforeUser.Group.Id != group.Id)
                 {
                     content = new UserMovedToGroupContent(beforeUser.Id, beforeUser.Group.Id, group.Id);
                 }