snapcraft.yaml: fix typo in ttysnoop wrapper

fix stupid typo in wrapper: ttysnop -> ttysnoop
Signed-off-by: Colin Ian King <colin.king@canonical.com>

snapcraft/snapcraft.yaml

@@ -119,7 +119,7 @@ apps:
     tcptop:
         command: wrapper tcptop
     ttysnoop:
-        command: wrapper ttysnop
+        command: wrapper ttysnoop
     trace:
         command: wrapper trace
     vfscount: