add proper scm options

Author: kodjo-anipah

pom.xml

@@ -27,9 +27,9 @@
     </licenses>
 
     <scm>
-        <url>https://github.com/graylog-labs/syslog4j-graylog2</url>
-        <connection>https://github.com/graylog-labs/syslog4j-graylog2.git</connection>
-        <developerConnection>https://github.com/graylog-labs/syslog4j-graylog2.git</developerConnection>
+        <url>scm:git:https://github.com/graylog-labs/syslog4j-graylog2</url>
+        <connection>scm:git:https://github.com/graylog-labs/syslog4j-graylog2.git</connection>
+        <developerConnection>scm:git:https://github.com/graylog-labs/syslog4j-graylog2.git</developerConnection>
         <tag>HEAD</tag>
     </scm>