[fractal] Fix warning: unused mut

[Jordan Petridis <jpetridis src gnome org>]

commit 09894a81b6c99d1953c2447f3fd8ddb7303008ba
Author: Alejandro Domínguez <adomu net-c com>
Date:   Mon Dec 31 16:07:18 2018 +0100

    Fix warning: unused mut

 fractal-gtk/src/app/connect/send.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/fractal-gtk/src/app/connect/send.rs b/fractal-gtk/src/app/connect/send.rs
index 299cf61f..dd9dfedd 100644
--- a/fractal-gtk/src/app/connect/send.rs
+++ b/fractal-gtk/src/app/connect/send.rs
@@ -44,8 +44,7 @@ impl App {
                     let end = buffer.get_end_iter();
 
                     if let Some(text) = buffer.get_text(&start, &end, false) {
-                        let mut mut_text = text;
-                        op.lock().unwrap().send_message(mut_text);
+                        op.lock().unwrap().send_message(text);
                     }
 
                     buffer.set_text("");