Revert "Add library `lucene-backward-codecs` to migrate indices."

This reverts commit 662fb9012fb6897c9b05c939232919797e665f38.
diff --git a/.classpath b/.classpath
index 5d96d16..42cbfbc 100644
--- a/.classpath
+++ b/.classpath
@@ -22,7 +22,6 @@
 	<classpathentry kind="lib" path="ext/wicket-auth-roles-1.4.22.jar" sourcepath="ext/src/wicket-auth-roles-1.4.22.jar" />
 	<classpathentry kind="lib" path="ext/wicket-extensions-1.4.22.jar" sourcepath="ext/src/wicket-extensions-1.4.22.jar" />
 	<classpathentry kind="lib" path="ext/lucene-core-5.5.2.jar" sourcepath="ext/src/lucene-core-5.5.2.jar" />
-	<classpathentry kind="lib" path="ext/lucene-backward-codecs-5.5.2.jar" sourcepath="ext/src/lucene-backward-codecs-5.5.2.jar" />
 	<classpathentry kind="lib" path="ext/lucene-analyzers-common-5.5.2.jar" sourcepath="ext/src/lucene-analyzers-common-5.5.2.jar" />
 	<classpathentry kind="lib" path="ext/lucene-highlighter-5.5.2.jar" sourcepath="ext/src/lucene-highlighter-5.5.2.jar" />
 	<classpathentry kind="lib" path="ext/lucene-memory-5.5.2.jar" sourcepath="ext/src/lucene-memory-5.5.2.jar" />
diff --git a/build.moxie b/build.moxie
index 2748eab..f21241d 100644
--- a/build.moxie
+++ b/build.moxie
@@ -145,7 +145,6 @@
 - compile 'org.apache.wicket:wicket-auth-roles:${wicket.version}' :war !org.mockito
 - compile 'org.apache.wicket:wicket-extensions:${wicket.version}' :war !org.mockito
 - compile 'org.apache.lucene:lucene-core:${lucene.version}' :war :fedclient
-- compile 'org.apache.lucene:lucene-backward-codecs:${lucene.version}' :war :fedclient
 - compile 'org.apache.lucene:lucene-analyzers-common:${lucene.version}' :war :fedclient
 - compile 'org.apache.lucene:lucene-highlighter:${lucene.version}' :war :fedclient !org.apache.lucene:lucene-join
 - compile 'org.apache.lucene:lucene-memory:${lucene.version}' :war :fedclient
diff --git a/gitblit.iml b/gitblit.iml
index 25a4447..1f4aa24 100644
--- a/gitblit.iml
+++ b/gitblit.iml
@@ -191,17 +191,6 @@
       </library>
     </orderEntry>
     <orderEntry type="module-library">
-      <library name="lucene-backward-codecs-5.5.2.jar">
-        <CLASSES>
-          <root url="jar://$MODULE_DIR$/ext/lucene-backward-codecs-5.5.2.jar!/" />
-        </CLASSES>
-        <JAVADOC />
-        <SOURCES>
-          <root url="jar://$MODULE_DIR$/ext/src/lucene-backward-codecs-5.5.2.jar!/" />
-        </SOURCES>
-      </library>
-    </orderEntry>
-    <orderEntry type="module-library">
       <library name="lucene-analyzers-common-5.5.2.jar">
         <CLASSES>
           <root url="jar://$MODULE_DIR$/ext/lucene-analyzers-common-5.5.2.jar!/" />