Update boxmaker.py

Decided to go with 0.002" instead of 0.001" - still should cut on Epilogs according to this page:
http://support.epiloglaser.com/article/8205/29827/cutting-and-engraving-different-line-weights 
and it makes the lines a little more visible on the screen.

boxmaker.py

@@ -266,7 +266,7 @@ class BoxMaker(inkex.Effect):
 
     # Set the line thickness
     if hairline:
-        linethickness=self.unittouu('0.001in')
+        linethickness=self.unittouu('0.002in')
     else:
         linethickness=1