Be explicit about jarsigner algorithms

If these aren't specified, it works fine with the jdk6 version, but
produces an unusable (on Android) index.jar with the jdk7 version.

buildserver/Vagrantfile

@@ -3,7 +3,7 @@ Vagrant::Config.run do |config|
   config.vm.box = "precise32"
   config.vm.box_url = "/shares/software/OS and Boot/precise32.box"
 
-  config.vm.customize ["modifyvm", :id, "--memory", "1536"]
+  config.vm.customize ["modifyvm", :id, "--memory", "2048"]
 
   config.vm.provision :shell, :path => "fixpaths.sh"
   # Set apt proxy - remove, or adjust this, accordingly!

fdroidserver/update.py

@@ -698,6 +698,7 @@ def main():
         # Sign the index...
         p = subprocess.Popen(['jarsigner', '-keystore', keystore,
             '-storepass', keystorepass, '-keypass', keypass,
+            '-digestalg', 'SHA1', '-sigalg', 'MD5withRSA',
             os.path.join('repo', 'index.jar') , repo_keyalias], stdout=subprocess.PIPE)
         output = p.communicate()[0]
         if p.returncode != 0: