issue #6473 Plantuml parse error

Small corrections:
- wrong line was deleted
- side effect with single backtick corrected

Author: albert-github

doc/commands.dox

@@ -3874,8 +3874,8 @@ class Receiver
   \ref cmdendhtmlonly "\\endhtmlonly" is inserted as-is. When you
   want to insert a HTML fragment that has block scope like a table or list
   which should appear outside \<p\>..\</p\>, this can lead to invalid HTML.
-  You can use `\htmlonly[block]` to make Doxygen
-  end the current paragraph and restart it after \\endhtmlonly.
+  You can use <tt>\\htmlonly[block]</tt> to make Doxygen
+  end the current paragraph and restart it after <tt>\\endhtmlonly</tt>.
 
   \note environment variables (like \$(HOME) ) are resolved inside a
   HTML-only block.

src/scanner.l

@@ -7076,8 +7076,8 @@ NONLopt [^\n]*
 <DocBlock>^({B}*"*"+)?{B}{0,3}"```"[`]*/"{"[^}]+"}" |
 <DocBlock>^({B}*"*"+)?{B}{0,3}"```"[`]* {
                                           QCString pat = substitute(yytext,"*"," ");
-                                          yyextra->docBlock << "\\iskip";
                                           if (Config_getBool(MARKDOWN_SUPPORT)) yyextra->docBlock << "\\iskip";
+                                          yyextra->docBlock << yytext;
                                           yyextra->docBlockName="```";
                                           yyextra->fencedSize=pat.stripWhiteSpace().length();
                                           yyextra->nestedComment=0;