Remove dead code in list.js

It was there because of the overly-defensive programming.

indentAfterMarker is set to 1 in line 159, it's never less than that

lib/rules_block/list.js

@@ -165,10 +165,6 @@ module.exports = function list(state, startLine, endLine, silent) {
     // (the rest is just indented code block)
     if (indentAfterMarker > 4) { indentAfterMarker = 1; }
 
-    // If indent is less than 1, assume that it's one, example:
-    //  "-\n  test"
-    if (indentAfterMarker < 1) { indentAfterMarker = 1; }
-
     // "  -  test"
     //  ^^^^^ - calculating total length of this thing
     indent = (posAfterMarker - state.bMarks[nextLine]) + indentAfterMarker;