try to fix travis build

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1891598 13f79535-47bb-0310-9956-ffa450edef68

.travis.yml

@@ -3,9 +3,9 @@ language: java
 jdk:
 - openjdk11
 before_install:
-  - wget https://www.apache.org/dist/ant/binaries/apache-ant-1.10.9-bin.tar.gz
-  - tar -xzvf apache-ant-1.10.9-bin.tar.gz
-  - export PATH=`pwd`/apache-ant-1.10.9/bin:$PATH
+  - wget https://archive.apache.org/dist/ant/binaries/apache-ant-1.10.11-bin.tar.gz
+  - tar -xzvf apache-ant-1.10.11-bin.tar.gz
+  - export PATH=`pwd`/apache-ant-1.10.11/bin:$PATH
   - echo $(ant -version)
   - svn co https://svn.apache.org/repos/asf/poi/site/src/documentation src/documentation
 install: /bin/true