Removed duplicate highlighting

eval_error.c

@@ -144,8 +144,6 @@ print_errinfo(const VALUE eclass, const VALUE errat, const VALUE emesg, const VA
 	    write_warn(str, ": ");
 	}
 
-	if (highlight) write_warn(str, bold);
-
 	if (!NIL_P(emesg)) {
 	    einfo = RSTRING_PTR(emesg);
             elen = RSTRING_LEN(emesg);

test/ruby/test_exception.rb

@@ -1407,6 +1407,9 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
 
     message = e.full_message(highlight: true)
     assert_match(/\e/, message)
+    assert_not_match(/(\e\[1)m\1/, message)
+    e2 = assert_raise(RuntimeError) {raise RuntimeError, "", bt}
+    assert_not_match(/(\e\[1)m\1/, e2.full_message(highlight: true))
 
     message = e.full_message
     if Exception.to_tty?