Update README for better formatting of Mac app build instructions

Author: jalessio

README.md

@@ -1,4 +1,3 @@
-
 WARNING:
 On MacOS 10.6 (at least up to 10.6.6), your network will
 stop responding about 10 minutes after the first time you
@@ -78,8 +77,7 @@ This is how you use it:
    local network attacks such as Firesheep and friends.
 
  - OR if you have MacOS and want to try the GUI version:
-        make
-        open ui-macos/Sshuttle*.app
+        `make && open ui-macos/Sshuttle*.app`
 
 (You may be prompted for one or more passwords; first, the
 local password to become root using either sudo or su, and