fix for two-nybble codepoints

unicodedomino.sty

@@ -28,7 +28,7 @@
 % makes all UTF-8 available in listings.
 
 \NeedsTeXFormat{LaTeX2e}%
-\ProvidesPackage{unicodedomino}[2018/08/05 1.2 Domino for unknown codepoints]%
+\ProvidesPackage{unicodedomino}[2018/08/05 1.3~ Domino for unknown codepoints]%
 \makeatletter%
 
 \ifx\numexpr\@undefined%
@@ -44,9 +44,11 @@
   U-000%
  \else\ifnum#1>4095%
   U+%
- \else%
+ \else\ifnum#1>255%
   U+0%
- \fi\fi%
+ \else%
+  U+00%
+ \fi\fi\fi%
  \expandafter\UTFviii@hexnumber\expandafter{#1}%
 }%
 
@@ -85,6 +87,7 @@
 \def\unicodedomino@hex@ll#1{%
  \ifnum#1<65536 0.\fi%
  \ifnum#1<4096 0.\fi%
+ \ifnum#1<256 0.\fi%
  \expandafter\unicodedomino@hex@ne\expandafter{#1}%
 }%
 % call the appropriate box function