Fix perltidy config for updated version

-vt, --vertical-tightness, was updated with a max value of 2 rather
than 4.

.perltidyrc

@@ -1,7 +1,7 @@
 -l=140   # Max line width is 140 cols
 -i=4     # Indent level is 4 cols
 -ci=4    # Continuation indent is 4 cols
--vt=4    # Maximal vertical tightness
+-vt=2    # Maximal vertical tightness
 -cti=0   # No extra indentation for closing brackets
 -pt=1    # Medium parenthesis tightness
 -sbt=1   # Medium square bracket tightness