When Shift + Tab is pressed X server send the event XK_ISO_Left_Tab with
ShiftMask, so this is the entry we need in config.def.h
This patch also revert the previous patch for this issue because it breaks
the keyboard.
---
config.def.h | 2 +-
st.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)