Bugfix. Declare converse-modal as a dependency of converse-message-view

Otherwise we get `TypeError: Cannot read property 'extend' of undefined`
when attempting to extend `BootstrapModal`.

CHANGES.md

@@ -2,6 +2,7 @@
 
 ## 4.0.5 (Unreleased)
 
+- `FATAL: TypeError: Cannot read property 'extend' of undefined` when using `embedded` view mode.
 
 ## 4.0.4 (2018-10-29)
 

dist/converse.js

@@ -61597,6 +61597,8 @@ const _converse$env = _converse_headless_converse_core__WEBPACK_IMPORTED_MODULE_
       _ = _converse$env._,
       moment = _converse$env.moment;
 _converse_headless_converse_core__WEBPACK_IMPORTED_MODULE_0__["default"].plugins.add('converse-message-view', {
+  dependencies: ["converse-modal"],
+
   initialize() {
     /* The initialize function gets called as soon as the plugin is
      * loaded by converse.js's plugin machinery.
@@ -73339,7 +73341,6 @@ const converse = {
    *
    * @example
    * converse.initialize({
-   *     allow_otr: true,
    *     auto_list_rooms: false,
    *     auto_subscribe: false,
    *     bosh_service_url: 'https://bind.example.com',

src/converse-message-view.js

@@ -20,6 +20,8 @@ const { Backbone, _, moment } = converse.env;
 
 converse.plugins.add('converse-message-view', {
 
+    dependencies: ["converse-modal"],
+
     initialize () {
         /* The initialize function gets called as soon as the plugin is
          * loaded by converse.js's plugin machinery.

src/headless/converse-core.js

@@ -1660,7 +1660,6 @@ const converse = {
      *
      * @example
      * converse.initialize({
-     *     allow_otr: true,
      *     auto_list_rooms: false,
      *     auto_subscribe: false,
      *     bosh_service_url: 'https://bind.example.com',