curl: Moved check for password out of get parameter loop

Moved the calls to checkpasswd() out of the getparameter() function
which allows for any related arguments to be specified on the command
line before or after --user (and --proxy-user).

For example: --bearer doesn't need to be specified before --user to
prevent curl from asking for an unnecessary password as is the case
with commit e7dcc454c67a2f.