Update MongoDB_FileWorkspaceMap.java

Author: rplauta

src/main/java/picoded/dstack/mongodb/MongoDB_FileWorkspaceMap.java

@@ -18,7 +18,6 @@
 // JavaCommons imports
 import picoded.core.common.EmptyArray;
 import picoded.core.file.FileUtil;
-import picoded.core.conv.ConvertJSON;
 import picoded.dstack.FileWorkspace;
 import picoded.dstack.core.Core_FileWorkspaceMap;