Declare source encoding UTF-8

Explicitly use UTF-8 so Cp1252 isn't otherwise used on Windows.

Author: ugexe

pom.xml

@@ -152,6 +152,9 @@
             </plugin>
         </plugins>
     </build>
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
     <profiles>
         <profile>
             <id>active-on-jdk-9-plus</id>