start-ssh: force umask to 077

Change-Id: Ie36338f174f891dee3f531d0b261d58e211d095f
diff --git a/start-ssh b/start-ssh
index b9d7218..9f4b233 100755
--- a/start-ssh
+++ b/start-ssh
@@ -1,5 +1,7 @@
 #!/system/bin/sh
 
+umask 077
+
 # DEBUG=1
 
 DSA_KEY=/data/ssh/ssh_host_dsa_key