I am having this same problem with a new install. I have tried everything listed here and nothing seems to work.
Warning: Cannot modify header information – headers already sent by (output started at /home/content/c/a/r/carlkiwi/html/wp-config.php:1) in /home/content/c/a/r/carlkiwi/html/wp-login.php on line 12
Warning: Cannot modify header information – headers already sent by (output started at /home/content/c/a/r/carlkiwi/html/wp-config.php:1) in /home/content/c/a/r/carlkiwi/html/wp-includes/pluggable.php on line 313
Warning: Cannot modify header information – headers already sent by (output started at /home/content/c/a/r/carlkiwi/html/wp-config.php:1) in /home/content/c/a/r/carlkiwi/html/wp-includes/pluggable.php on line 314
Warning: Cannot modify header information – headers already sent by (output started at /home/content/c/a/r/carlkiwi/html/wp-config.php:1) in /home/content/c/a/r/carlkiwi/html/wp-includes/pluggable.php on line 275
