Trivial: fix comments referencing AppInit2

It was refactored into multiple functions in
0cc8b6bc44.

src/init.cpp

@@ -118,10 +118,6 @@ static const char* FEE_ESTIMATES_FILENAME="fee_estimates.dat";
 // threads that should only be stopped after the main network-processing
 // threads have exited.
 //
-// Note that if running -daemon the parent process returns from AppInit2
-// before adding any threads to the threadGroup, so .join_all() returns
-// immediately and the parent exits from main().
-//
 // Shutdown for Qt is very similar, only it uses a QTimer to detect
 // fRequestShutdown getting set, and then does the normal Qt
 // shutdown thing.
@@ -188,7 +184,7 @@ void Shutdown()
     if (!lockShutdown)
         return;
 
-    /// Note: Shutdown() must be able to handle cases in which AppInit2() failed part of the way,
+    /// Note: Shutdown() must be able to handle cases in which initialization failed part of the way,
     /// for example if the data directory was found to be locked.
     /// Be sure that anything that writes files or flushes caches only does this if the respective
     /// module was initialized.