debugger: streamline classical dumper setup

Remote dumpers are not used anymore, there's also no need to
have it in the engine base class anymore.

Change-Id: If0b6930b07e468d5973d848e02696bc5da40a197
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/gdb/gdbengine.h

@@ -646,7 +646,6 @@ protected:
     bool checkDebuggingHelpersClassic();
     void setDebuggingHelperStateClassic(DebuggingHelperState);
     void tryLoadDebuggingHelpersClassic();
-    void tryQueryDebuggingHelpersClassic();
 
     DebuggingHelperState m_debuggingHelperState;
     DumperHelper m_dumperHelper;