onecode: Fix vertical alignment of default text

Author: terryburton

src/onecode.ps.src

@@ -364,7 +364,7 @@ begin
     /txt txt
     /textxalign (left)
     /textfont /Helvetica
-    /textyoffset 1.0
+    /textyoffset -1.0
     /textxoffset -0.3
     /opt options
     >>