pom: enforce utf-8 encoding

keep maven happy

Acked-by: Olufemi Adeyemi
Target: master

pom.xml

@@ -43,6 +43,10 @@
       <module>benchmarks</module>
   </modules>
 
+  <properties>
+      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
   <build>
     <pluginManagement>
       <plugins>