patch 9.1.0125: unused init of text_prop_idxs in win_line()

patch 9.1.0125: unused init of text_prop_idxs in win_line()

Problem:  unused init of text_prop_idxs in win_line
Solution: Remove it, fix typo
          (Dylan Thacker-Smith)

Later use of text_prop_idxs treats it as empty, incrementing
text_props_active as new elements are added to this array, so remove
this unused conditional initialization when text_props_active is 0.

closes: #14063

Signed-off-by: Dylan Thacker-Smith <dylan.ah.smith@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>