[source] dropbear: fix procd interface trigger install

[LEDE Commits]

jow pushed a commit to source.git, branch lede-17.01:
https://git.lede-project.org/f30114c7c427a9568d56578560aad9cf5839e4df

commit f30114c7c427a9568d56578560aad9cf5839e4df
Author: Hans Dedecker <dedeckeh at gmail.com>
AuthorDate: Wed Apr 26 16:44:02 2017 +0200

    dropbear: fix procd interface trigger install
    
    Install procd interface triggers only for interfaces which are enabled
    so dropbear instances running on (an) enabled interface(s) are not
    restarted due to an interface trigger of an interface which is disabled.
    
    Signed-off-by: Hans Dedecker <dedeckeh at gmail.com>
    (cherry picked from commit e5bbead1a83944293fccc27679ba9846d133374e)
---
 package/network/services/dropbear/files/dropbear.init | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/package/network/services/dropbear/files/dropbear.init b/package/network/services/dropbear/files/dropbear.init
index 5c21359..2d23ebd 100755
--- a/package/network/services/dropbear/files/dropbear.init
+++ b/package/network/services/dropbear/files/dropbear.init
@@ -109,7 +109,9 @@ keygen()
 load_interfaces()
 {
 	config_get interface "$1" Interface
-	interfaces=" ${interface} ${interfaces}"
+	config_get enable "$1" enable 1
+
+	[ "${enable}" = "1" ] && interfaces=" ${interface} ${interfaces}"
 }
 
 start_service()