Fix trivial bug in 'all' module

src/graph_tool/all.py

@@ -44,7 +44,7 @@ import graph_tool.clustering
 from graph_tool.community import *
 import graph_tool.community
 from graph_tool.run_action import *
-graph_tool.run_action
+import graph_tool.run_action
 from graph_tool.topology import *
 import graph_tool.topology
 from graph_tool.flow import *