The wireless-security setting has a 'wep-key-type' property that is
used to specify the WEP key type and is needed because some keys could
be interpreted both as a passphrase or a hex/ascii key.

The ifcfg-rh plugin currently stores the key type implicitly: if
wep-key-type is 'passphrase' it uses the KEY_PASSPHRASE%d variable, if
it's 'key' the KEY%d variable and when it's 'unknown' it uses either
variables depending on the detected type (preferring 'key' in case
both are compatible).

This means that some connections will be read differently from how
they were written, because once the KEY (or KEY_PASSPHRASE) is read
there is no way to know whether the 'wep-key-type' property was 'key'
(or 'passphrase') or 'unknown'.

Fix this by persisting the key type explicitly in the file. The new
variable is redundant in most cases because the variables used for
keys also determine the key type.

https://bugzilla.redhat.com/show_bug.cgi?id=1518177