fix _ofind attr in %page

_ofind is a shell attr, not Magics attr

closes  #1960

IPython/core/magics/basic.py

@@ -185,7 +185,7 b' Currently the magic system has the following functions:""",'
         raw = 'r' in opts
 
         oname = args and args or '_'
-        info = self._ofind(oname)
+        info = self.shell._ofind(oname)
         if info['found']:
             txt = (raw and str or pformat)( info['obj'] )
             page.page(txt)