Save ACCOUNT_KEY_PATH and ACCOUNT_EMAIL in _initconf()

this enables the following one liner for initial
configuration at install time, which would mean that most
users would never need to touch their account.conf
manually:

ACCOUNT_KEY_PATH=/path/to/account.key ACCOUNT_EMAIL=some@valid.email ./le.sh install

le.sh

@@ -1651,6 +1651,14 @@ USER_AGENT=\"le.sh client: $PROJECT\"
 #CX_Secret=\"sADDsdasdgdsf\"
 
     " > $ACCOUNT_CONF_PATH
+
+    if [[ -n "$ACCOUNT_KEY_PATH" && "$ACCOUNT_KEY_PATH" != "$LE_WORKING_DIR/account.key" ]]; then
+      _saveaccountconf "ACCOUNT_KEY_PATH" "$ACCOUNT_KEY_PATH"
+    fi
+
+    if [[ -n "ACCOUNT_EMAIL" ]]; then
+      _saveaccountconf "ACCOUNT_EMAIL" "$ACCOUNT_EMAIL"
+    fi
   fi
 }