Fix weird plugin path construction.

We have a path, it doesn't really make sense to take the filename,
then take the directory, then create a new path using those...

src/com/dmdirc/plugins/PluginInfo.java

@@ -39,7 +39,6 @@ import java.nio.file.FileSystems;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
@@ -111,7 +110,6 @@ public class PluginInfo implements ServiceProvider {
     public PluginInfo(
             final PluginManager pluginManager,
             final ServiceManager serviceManager,
-            final String pluginDirectory,
             final PluginMetaData metadata,
             final DMDircMBassador eventBus,
             final IdentityController identityController,
@@ -125,7 +123,7 @@ public class PluginInfo implements ServiceProvider {
         this.metaData = metadata;
 
         try {
-            pluginFilesystem = FileSystems.newFileSystem(Paths.get(pluginDirectory, filename), null);
+            pluginFilesystem = FileSystems.newFileSystem(metadata.getPluginPath(), null);
         } catch (IOException ex) {
             lastError = "Error loading filesystem: " + ex.getMessage();
             throw new PluginException("Plugin " + filename + " failed to load. " + lastError, ex);

src/com/dmdirc/plugins/PluginManager.java

@@ -149,7 +149,7 @@ public class PluginManager {
             final PluginMetaData metadata = new PluginMetaData(this,
                     Paths.get(directory, filename));
             metadata.load();
-            final PluginInfo pluginInfo = new PluginInfo(this, serviceManager, directory, metadata,
+            final PluginInfo pluginInfo = new PluginInfo(this, serviceManager, metadata,
                     eventBus, identityController, objectGraph);
             final PluginInfo existing = getPluginInfoByName(metadata.getName());
             if (existing != null) {