Revert "configure: Change default of CFG_REDUCE_RELOCATIONS to "no"."

This reverts commit d0eba497

.

A better fix is to use -fPIC instead of just -fPIE fo
-reduce-relocations.

Task-number: QTBUG-45755
Change-Id: I1759291b684fd76d4009e4be9ba1354eb056e659
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>