Build http.server source JAR

Change-Id: I459de081fd518abfa50dd812c68eed4d1c7f8a0b
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

org.eclipse.jgit.http.server/pom.xml

@@ -96,6 +96,26 @@
     </resources>
 
     <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-source-plugin</artifactId>
+        <inherited>true</inherited>
+        <executions>
+          <execution>
+            <id>attach-sources</id>
+            <phase>process-classes</phase>
+            <goals>
+              <goal>jar</goal>
+            </goals>
+            <configuration>
+              <archive>
+                <manifestFile>${source-bundle-manifest}</manifestFile>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+
       <plugin>
         <artifactId>maven-jar-plugin</artifactId>
         <configuration>