ensure there is always an $EDITOR set

It could occur that a user does not have an $EDITOR set when logging in
via SSH.

Signed-off-by: Stacy Harper <contact@stacyharper.net>

scripts/core/sxmo_common.sh

@@ -21,6 +21,7 @@ export CONTACTFILE="$XDG_CONFIG_HOME/sxmo/contacts.tsv"
 export MODEMSTATEFILE="$XDG_RUNTIME_DIR/sxmo.modem.state"
 
 command -v "$KEYBOARD" > /dev/null || export KEYBOARD=svkbd-mobile-intl
+command -v "$EDITOR" > /dev/null || export EDITOR=vis
 
 # This script ensures all sxmo scripts are using the busybox version of
 # certain coreutils rather than any other version that may be installed on the