Update com.jcraft.jsch to 0.1.50 also in pom dependencies

We updated the target platforms in 3.3 following the version shipped
by the release train but missed to update it in pom dependencies.
This wasn't harmful as there were no API changes between 0.1.46 and
0.1.50.

Change-Id: Ie8ac2ea447fa93d6643b9817f58767ab7f0b1aa4
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

pom.xml

@@ -176,7 +176,7 @@
     <bundle-manifest>${project.build.directory}/META-INF/MANIFEST.MF</bundle-manifest>
 
     <jgit-last-release-version>3.2.0.201312181205-r</jgit-last-release-version>
-    <jsch-version>0.1.46</jsch-version>
+    <jsch-version>0.1.50</jsch-version>
     <javaewah-version>0.7.9</javaewah-version>
     <junit-version>4.11</junit-version>
     <!-- TODO: update Maven dependency for args4j to 2.0.21 as soon as available on Maven Central -->