use dedent in rst.nim, refs nim-lang#17257 (comment)

lib/packages/docutils/rst.nim

@@ -2253,8 +2253,7 @@ proc parseEnumList(p: var RstParser): PRstNode =
               (should be at column $3 if it's a continuation of enum. list),
           or no blank line after line $1 (if it should be the next paragraph),
           or no escaping \ at the beginning of line $1
-              (if lines $1..$2 are a normal paragraph, not enum. list)""".
-          unindent(8)
+              (if lines $1..$2 are a normal paragraph, not enum. list)""".dedent
         let c = p.col + requiredIndent + ColRstOffset
         rstMessage(p, mwRstStyle, msg % [$(n-1), $n, $c],
                    p.tok[j].line, p.tok[j].col)