Fix keymap being NULL and segfaulting on dev add

Moved `libinput_config` to the callers of
`sway_input_configure_libinput_device` so that we send the event after
the added event.

include/sway/input/libinput.h

@@ -2,7 +2,7 @@
 #define _SWAY_INPUT_LIBINPUT_H
 #include "sway/input/input-manager.h"
 
-void sway_input_configure_libinput_device(struct sway_input_device *device);
+bool sway_input_configure_libinput_device(struct sway_input_device *device);
 
 void sway_input_reset_libinput_device(struct sway_input_device *device);
 

sway/input/input-manager.c

@@ -236,7 +236,7 @@ static void handle_new_input(struct wl_listener *listener, void *data) {
 
 	apply_input_type_config(input_device);
 
-	sway_input_configure_libinput_device(input_device);
+	bool config_changed = sway_input_configure_libinput_device(input_device);
 
 	wl_signal_add(&device->events.destroy, &input_device->device_destroy);
 	input_device->device_destroy.notify = handle_device_destroy;
@@ -274,6 +274,10 @@ static void handle_new_input(struct wl_listener *listener, void *data) {
 	}
 
 	ipc_event_input("added", input_device);
+
+	if (config_changed) {
+		ipc_event_input("libinput_config", input_device);
+	}
 }
 
 static void handle_inhibit_activate(struct wl_listener *listener, void *data) {
@@ -528,11 +532,14 @@ static void retranslate_keysyms(struct input_config *input_config) {
 
 static void input_manager_configure_input(
 		struct sway_input_device *input_device) {
-	sway_input_configure_libinput_device(input_device);
+	bool config_changed = sway_input_configure_libinput_device(input_device);
 	struct sway_seat *seat = NULL;
 	wl_list_for_each(seat, &server.input->seats, link) {
 		seat_configure_device(seat, input_device);
 	}
+	if (config_changed) {
+		ipc_event_input("libinput_config", input_device);
+	}
 }
 
 void input_manager_configure_all_inputs(void) {

sway/input/libinput.c

@@ -187,10 +187,10 @@ static bool set_calibration_matrix(struct libinput_device *dev, float mat[6]) {
 	return changed;
 }
 
-void sway_input_configure_libinput_device(struct sway_input_device *input_device) {
+bool sway_input_configure_libinput_device(struct sway_input_device *input_device) {
 	struct input_config *ic = input_device_get_config(input_device);
 	if (!ic || !wlr_input_device_is_libinput(input_device->wlr_device)) {
-		return;
+		return false;
 	}
 
 	struct libinput_device *device =
@@ -259,9 +259,7 @@ void sway_input_configure_libinput_device(struct sway_input_device *input_device
 		changed |= set_calibration_matrix(device, ic->calibration_matrix.matrix);
 	}
 
-	if (changed) {
-		ipc_event_input("libinput_config", input_device);
-	}
+	return changed;
 }
 
 void sway_input_reset_libinput_device(struct sway_input_device *input_device) {