FOP-2935: Make servlet a compile only dependency

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1878031 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/fop-core/pom.xml b/fop-core/pom.xml
index 01e2f87..18175d8 100644
--- a/fop-core/pom.xml
+++ b/fop-core/pom.xml
@@ -81,6 +81,7 @@
       <groupId>javax.servlet</groupId>
       <artifactId>servlet-api</artifactId>
       <version>2.2</version>
+      <scope>compile</scope>
     </dependency>
     <dependency>
       <groupId>org.apache.ant</groupId>