Update javax.servlet dependency

fop-core/pom.xml

@@ -89,10 +89,9 @@
       <version>${commons.logging.version}</version>
     </dependency>
     <dependency>
-      <groupId>javax.servlet</groupId>
-      <artifactId>servlet-api</artifactId>
-      <version>2.2</version>
-      <scope>provided</scope>
+        <groupId>javax.servlet</groupId>
+        <artifactId>javax.servlet-api</artifactId>
+        <version>3.1.0</version>
     </dependency>
     <dependency>
       <groupId>org.apache.ant</groupId>