reduce grpc version

Author: jeffyecn

pom.xml

@@ -45,7 +45,7 @@
         <plugin.protobuf.version>0.5.1</plugin.protobuf.version>
         <plugin.source.version>3.0.1</plugin.source.version>
         <!-- dependency version -->
-        <grpc.version>1.10.0</grpc.version>
+        <grpc.version>1.9.0</grpc.version>
         <junit.version>4.12</junit.version>
         <log4j.version>1.2.17</log4j.version>
         <protobuf.version>3.5.1</protobuf.version>