qtbase: disable gdb_dwarf_index
qtbase: disable gdb_dwarf_index

* qmake is trying to call native gdb and we don't depend on gdb-native
  (or even provide gdb-native)
* fixes errors like this:
  /bin/sh: gdb: command not found
  /bin/sh: line 0: test: -gt: unary operator expected
  which are not fatal, but still misleading in do_configure output

sapiippo/meta-qt5,timopulkkinen/meta-qt5,jruffin/meta-qt5,cjp256/meta-qt5,timopulkkinen/meta-qt5,timopulkkinen/meta-qt5,opendreambox/meta-qt5,timopulkkinen/meta-qt5,schnitzeltony/meta-qt5,Tofee/meta-qt5,opendreambox/meta-qt5,kraj/meta-qt5,meta-qt5/meta-qt5,Tofee/meta-qt5,kraj/meta-qt5,schnitzeltony/meta-qt5,sapiippo/meta-qt5,jruffin/meta-qt5,meta-qt5/meta-qt5,Ivan-SB/meta-qt5,opendreambox/meta-qt5,Ivan-SB/meta-qt5,cjp256/meta-qt5