plugins/__init__.py: remove some unused? imports

plugins/__init__.py

@@ -30,12 +30,8 @@
 
 import gc
 import os
-import re
 import csv
-import sys
-import math
 import time
-import random
 import fnmatch
 import os.path
 import threading
@@ -44,16 +40,6 @@ import collections
 from .. import callbacks, conf, dbi, ircdb, ircutils, log, utils, world
 from ..commands import *
 
-try:
-    import sqlite3
-except ImportError:
-    raise ImportError('Cannot find sqlite3 module. If you are seeing this '
-            'message, it means you are running a non-standard Python '
-            'distribution that has not been compiled with sqlite3 support. '
-            'Please recompile it with sqlite3 support or report a bug to '
-            'the maintainer of the python package of your distribution.')
-
-
 class NoSuitableDatabase(Exception):
     def __init__(self, suitable):
         self.suitable = suitable