Don't fail if version.properties is unreadable

Fixes issue #42

acme4j-client/src/main/java/org/shredzone/acme4j/connector/HttpConnector.java

@@ -40,7 +40,7 @@ public class HttpConnector {
             Properties prop = new Properties();
             prop.load(in);
             agent.append('/').append(prop.getProperty("version"));
-        } catch (IOException ex) {
+        } catch (Exception ex) {
             // Ignore, just don't use a version
             LoggerFactory.getLogger(HttpConnector.class).warn("Could not read library version", ex);
         }