The console task shouldn't depend on compile

You should call it explicitly if you like, because compile task always
relink and install the shared object. It is possible to avoid it
externally, like I've done in this Makefile[1].

[1]: trondn/sdktools#14

Change-Id: Ie2e212f4e706edba9d1212113ca968f8c67f82c7
Reviewed-on: http://review.couchbase.org/24599
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>

tasks/util.rake

@@ -16,6 +16,6 @@
 #
 
 desc 'Start an irb session and load the library.'
-task :console => :compile do
+task :console do
   exec "irb -I lib -rcouchbase"
 end