Update authreg_mysql.c

Changed default password hashing algorithm from MD5 to SHA512 with 50000 rounds and a 22 character salt, to improve security against offline password cracking attacks.
Update authreg_mysql.c

array +1 error fixed.
Merge pull request #43 from goodvikings/master

MySQL hashed password algorithm change

from MD5 to SHA512 with 50000 rounds and a 22 character salt,
to improve security against offline password cracking attacks