[kupfer] core: Check if module exists before unloading at plugin unload

[Ulrik Sverdrup <usverdrup src gnome org>]

commit 1a4b0a18b700c74a6b24a6f3b9d0f17974035406
Author: Ulrik Sverdrup <ulrik sverdrup gmail com>
Date:   Thu Mar 3 02:11:30 2011 +0100

    core: Check if module exists before unloading at plugin unload

 kupfer/core/plugins.py |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/kupfer/core/plugins.py b/kupfer/core/plugins.py
index 6de86ba..2ec6ff8 100644
--- a/kupfer/core/plugins.py
+++ b/kupfer/core/plugins.py
@@ -379,7 +379,8 @@ def unimport_plugin(plugin_name):
 	del _imported_plugins[plugin_name]
 	plugin_module_name = ".".join(_plugin_path(plugin_name))
 	pretty.print_debug(__name__, "Dereferencing module", plugin_module_name)
-	sys.modules.pop(plugin_module_name)
+	if plugin_module_name in sys.modules:
+		sys.modules.pop(plugin_module_name)
 	for mod in list(sys.modules):
 		if mod.startswith(plugin_module_name + "."):
 			pretty.print_debug(__name__, "Dereferencing module", mod)