Fix new project dialog allowing creation of new code projects even if an IDE is not installed.

#rb none
#jira UE-71070
#rnx

[CL 5343356 by Ben Marsh in 4.22 branch]

Engine/Source/Developer/SourceCodeAccess/Private/SourceCodeAccessModule.cpp

@@ -86,7 +86,7 @@ bool FSourceCodeAccessModule::IsSourceCodeAccessorAvailable(FName Name) const
 	{
 		if (Accessor->GetFName() == Name)
 		{
-			return true;
+			return Accessor->CanAccessSourceCode();
 		}
 	}
 	return false;