tesseract-ocr: changed to use a dedicated datadir when prefix_auto is set

Note:

This influences the search path for language files.
The common path for language files is $datadir/tessdata.

graphic/tesseract-ocr/tesseract-ocr.conf

@@ -14,3 +14,8 @@
 
 # we need to run autogen.sh to generate Makefile templates
 autogen=1
+
+if [ $prefix_auto = 1 ]; then
+	# use a dedicated datadir
+	datadir="$datadir/$pkg"
+fi