apiclient: Bump Jackson version to 2.10.4

Jackson 2.9.x has various vulnerabilities that are fixed in 2.10 series:

FasterXML/jackson-databind#2700 (comment)

Let's update to the latest version of Jackson. This is a similar fix to
Github's Dependabot proposal, except we bump the version number across
all Jackson components:

#116

Author: penberg

scylla-apiclient/pom.xml

@@ -12,6 +12,7 @@
     <properties>
         <maven.compiler.target>1.8</maven.compiler.target>
         <maven.compiler.source>1.8</maven.compiler.source>
+        <jackson.version>2.10.4</jackson.version>
     </properties>
 
     <dependencies>
@@ -63,17 +64,17 @@
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-annotations</artifactId>
-            <version>2.9.9</version>
+            <version>${jackson.version}</version>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
-            <version>2.9.10.4</version>
+            <version>${jackson.version}</version>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.jaxrs</groupId>
             <artifactId>jackson-jaxrs-json-provider</artifactId>
-            <version>2.9.9</version>
+	    <version>${jackson.version}</version>
         </dependency>
     </dependencies>