Use standard size for new group conversation modal

Signed-off-by: Marco Ambrosini <marcoambrosini@pm.me>

src/components/LeftSidebar/NewGroupConversation/NewGroupConversation.vue

@@ -33,7 +33,6 @@
 		<!-- New group form -->
 		<Modal
 			v-if="modal"
-			size="full"
 			@close="closeModal">
 			<!-- Wrapper for content & navigation -->
 			<div