message: Per Pierre-Loup: Single 'z' key to zoom in/out on graph
diff: @@ -1642,12 +1642,12 @@ void TraceWin::graph_handle_hotkeys( graph_info_t &gi )
  }
  }
  }
  - else if ( ImGui::IsWindowFocused() &&
  - ( ImGui::IsKeyPressed( 'a' ) || ImGui::IsKeyPressed( 'b' ) ) )
  + else if ( ImGui::IsWindowFocused() && ImGui::IsKeyPressed( 'z' ) )
  {
  int64_t mouse_ts = gi.screenx_to_ts( gi.mouse_pos.x );
  + int64_t newlen = ( m_graph.length_ts >= 30 * MSECS_PER_SEC ) ?
  + 3 * MSECS_PER_SEC : 100 * MSECS_PER_SEC;
  - int64_t newlen = ImGui::IsKeyPressed( 'a' ) ? 3 * MSECS_PER_SEC : 100 * MSECS_PER_SEC;
  graph_zoom( mouse_ts, gi.ts0, false, newlen );
  }
  }
  