Avoid error if group header is not set

src/guards/groups.guards.ts

@@ -20,8 +20,15 @@ export class GroupsGuard implements CanActivate {
 
     // Get the group from the header
     const request = context.switchToHttp().getRequest();
-    const consumerGroups = request.headers[this.configService.config.groupHeader].split(',').map(e => e.trim());
+    const groupHeader = request.headers[this.configService.config.groupHeader];
+
+    if (!groupHeader) {
+      return false;
+    }
+
+    const consumerGroups = groupHeader.split(',').map(e => e.trim());
     const hasGroup = () => consumerGroups.some((group) => groups.includes(group));
+
     return consumerGroups && hasGroup();
   }
 }
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