Update nano to 2.9.5

Release Notes:
 2018 March 29
 GNU nano 2.9.5 "Kiša pada" changes the way the Scroll-Up
 and Scroll-Down commands work (M-- and M-+): instead of
 keeping the cursor in the same screen position they now
 keep the cursor in the same text position (if possible).
 This version further adds a new color name, "normal",
 which gives the default foreground or background color,
 which is useful when you want to undo some overzealous
 painting by earlier syntax regexes.  Bug fixes include:
 a segfault when trying to insert a file in restricted
 mode, the reading in of a new file being "undoable", a
 slight miswrapping of help texts when --linenumbers was
 used, and the shell syntax coloring the word "tar" in
 file names.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>