Upgrade webx version to fix dubbo-admin incompatible problem when running with jdk1.8

Author: chickenlj

pom.xml

@@ -110,8 +110,8 @@
         <sca_version>2.0-M5.1</sca_version>
         <guice_version>3.0</guice_version>
         <cglib_version>2.2</cglib_version>
-        <webx_version>3.0.8</webx_version>
-        <velocity_version>3.1.6</velocity_version>
+        <webx_version>3.1.6</webx_version>
+        <velocity_version>1.7</velocity_version>
         <!-- Log libs -->
         <slf4j_version>1.7.25</slf4j_version>
         <jcl_version>1.2</jcl_version>