Disable single instance check for integration tests

Causes a SIGABRT on mono 6.10 and 6.12 - double free or corruption

src/NzbDrone.Common/EnvironmentInfo/StartupContext.cs

@@ -24,6 +24,7 @@ namespace NzbDrone.Common.EnvironmentInfo
         public const string TERMINATE = "terminateexisting";
         public const string RESTART = "restart";
         public const string REGISTER_URL = "registerurl";
+        public const string NO_SINGLE_INSTANCE_CHECK = "nosingleinstancecheck";
 
         public StartupContext(params string[] args)
         {

src/NzbDrone.Common/Processes/ProcessProvider.cs

@@ -340,8 +340,6 @@ namespace NzbDrone.Common.Processes
             //TODO: move this to an OS specific class
             var monoProcesses = Process.GetProcessesByName("mono")
                                        .Union(Process.GetProcessesByName("mono-sgen"))
-                                       .Union(Process.GetProcessesByName("mono-sgen32"))
-                                       .Union(Process.GetProcessesByName("mono-sgen64"))
                                        .Where(process =>
                                               process.Modules.Cast<ProcessModule>()
                                                      .Any(module =>

src/NzbDrone.Host/Bootstrap.cs

@@ -93,6 +93,11 @@ namespace NzbDrone.Host
 
         private static void EnsureSingleInstance(bool isService, IStartupContext startupContext)
         {
+            if (startupContext.Flags.Contains(StartupContext.NO_SINGLE_INSTANCE_CHECK))
+            {
+                return;
+            }
+
             var instancePolicy = _container.Resolve<ISingleInstancePolicy>();
 
             if (startupContext.Flags.Contains(StartupContext.TERMINATE))

src/NzbDrone.Test.Common/NzbDroneRunner.cs

@@ -145,7 +145,7 @@ namespace NzbDrone.Test.Common
         {
             TestContext.Progress.WriteLine("Starting instance from {0} on port {1}", outputNzbdroneConsoleExe, Port);
 
-            var args = "-nobrowser -data=\"" + AppData + "\"";
+            var args = "-nobrowser -nosingleinstancecheck -data=\"" + AppData + "\"";
             _nzbDroneProcess = _processProvider.Start(outputNzbdroneConsoleExe, args, null, OnOutputDataReceived, OnOutputDataReceived);
         }