[gnome-terminal] help: Fix a typo

[Egmont Koblinger <egmontkob src gnome org>]

commit 1de112ff4403f0f52fea1a2bf074714cf145d2f9
Author: Egmont Koblinger <egmont gmail com>
Date:   Thu Mar 19 21:50:34 2020 +0100

    help: Fix a typo
    
    https://gitlab.gnome.org/GNOME/gnome-terminal/issues/234

 help/C/app-zoom.page | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/help/C/app-zoom.page b/help/C/app-zoom.page
index e917b31c..b8be1fdb 100644
--- a/help/C/app-zoom.page
+++ b/help/C/app-zoom.page
@@ -46,7 +46,7 @@
   <steps>
     <item>
       <p>Press the menu button in the top-right corner of the window and press
-      <gui style="button">+</gui>, or press
+      <gui style="button">-</gui>, or press
       <keyseq><key>Ctrl</key><key>-</key></keyseq>.</p>
     </item>
   </steps>