fix indentation, add comment for future TL compat

unicodedomino.sty

@@ -177,11 +177,14 @@
    \PackageWarning{inputenc}{%
     Unicode\space char\space\expandafter\UTFviii@splitcsname\string#1\relax%
     \space not\space set\space up\space for\space use\MessageBreak with\space%
-    LaTeX, replacing}%
-    \expandafter\unicodedomino@decode\string#1\relax%
-   \else%
-    % protected, just write the original character
-    \expandafter\@gobblefour\string#1%
+    LaTeX, replacing%
+   }%
+   % note: same warning as in \UTFviii@undefined@err in utf8.def v1.2c,
+   % except adding “, replacing” at the end and not being an error
+   \expandafter\unicodedomino@decode\string#1\relax%
+  \else%
+   % protected, just write the original character
+   \expandafter\@gobblefour\string#1%
   \fi%
  \else%
   % known char, expand