core: fix regex error for modules parameters

[snen]

Ambiguous was possible in params for multiple modules in one config line.
For example

loadmodule "presence_dialoginfo.so"
modparam("presence|dialplan", "db_url", "mysql://DBUSER:DBPASSWORD@localhost/DBNAME")

produced error
parameter <db_url> of type <1> not found in module <presence_dialoginfo>
because of ["presence_dialoginfo" =~ /^presence|dialplan$/] => True

[miconda]

The size in pkg_malloc() needs to be increased, too -- from:

    reg = pkg_malloc(len + 2 + 1);

to:

    reg = pkg_malloc(len + 4 + 1);

[snen]

right you are!
changed