Drop unused init.h includes

These were entirely unused, as based on successful compilation
and a grep for:
  \bStartShutdown\(\)|\bShutdownRequested\(\)|\bInterrupt\(\)|\bShutdown\(\)|\bInitLogging\(\)|\bInitParameterInteraction\(\)|\bAppInitBasicSetup\(\)|\bAppInitParameterInteraction\(\)|\bAppInitSanityChecks\(\)|\bAppInitLockDataDirectory\(\)|\bAppInitMain\(\)|\bSetupServerArgs\(\)|\bLicenseInfo\(\)|g_wallet_init_interface|init.h

src/qt/bitcoingui.cpp

@@ -29,7 +29,6 @@
 #endif
 
 #include <chainparams.h>
-#include <init.h>
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
 #include <ui_interface.h>