./configure: fix the tools pattern recognition
- when a variable name was given, with no regexp, the pattern did not correctly extract the variable name

/trunk/configure | 11 8 3 0 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

 # Compute IA-64-specific values

 CT_DoArchTupleValues() {

     # The architecture part of the tuple:

     CT_TARGET_ARCH="${CT_ARCH}"

 }