Merge pull request #555 from apache/fix_pom_xml_header

Fix pom xml header
diff --git a/pom.xml b/pom.xml
index da2d60b..35107f2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -18,9 +18,9 @@
 under the License.
 -->
 
-<project xmlns="https://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="https://maven.apache.org/POM/4.0.0
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
                              https://maven.apache.org/xsd/maven-4.0.0.xsd">
 
   <modelVersion>4.0.0</modelVersion>