Fix a build error

which occurred when -Pcoverage was not specified

pom.xml

@@ -87,6 +87,9 @@
     </profile>
     <profile>
       <id>coverage</id>
+      <properties>
+        <test.jvm.argLine.coverage>${jacoco.argLine}</test.jvm.argLine.coverage>
+      </properties>
       <build>
         <plugins>
           <plugin>
@@ -99,6 +102,9 @@
                 <goals>
                   <goal>prepare-agent</goal>
                 </goals>
+                <configuration>
+                  <propertyName>jacoco.argLine</propertyName>
+                </configuration>
               </execution>
             </executions>
           </plugin>
@@ -111,6 +117,7 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <jboss.marshalling.version>1.3.18.GA</jboss.marshalling.version>
+    <test.jvm.argLine.coverage></test.jvm.argLine.coverage> <!-- Set when 'coverage' profile is active -->
     <test.jvm.argLine>
       -server 
       -dsa -da -ea:io.netty...
@@ -468,7 +475,7 @@
             <exclude>**/TestUtil*</exclude>
           </excludes>
           <runOrder>random</runOrder>
-          <argLine>${argLine} ${test.jvm.argLine}</argLine>
+          <argLine>${test.jvm.argLine.coverage} ${test.jvm.argLine}</argLine>
         </configuration>
       </plugin>
       <!-- always produce osgi bundles -->