Bumped version of gRPC to 1.3.1

Change-Id: I7798476bd443a796e0e6a6e149ab8f66435ba4fa
diff --git a/protocols/p4runtime/pom.xml b/protocols/p4runtime/pom.xml
index 1f19b72..ab43ca0 100644
--- a/protocols/p4runtime/pom.xml
+++ b/protocols/p4runtime/pom.xml
@@ -42,7 +42,7 @@
         <dependency>
             <groupId>io.grpc</groupId>
             <artifactId>grpc-core</artifactId>
-            <version>1.3.0</version>
+            <version>1.3.1</version>
         </dependency>