Don't set page segmentation mode for unlv config

Setting the page segmentation mode to 6 ("Assume a single uniform block
of text") typically improves the layout detection for such texts, but
should not be done in the config file.

unlvtests/runtestset.sh adds `--psm 6` explicitly, so test results
won't change when using that script.

This is similar to commit ecfee53.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

tessdata/configs/unlv

@@ -1,2 +1 @@
 tessedit_write_unlv 1
-tessedit_pageseg_mode 6