Fix typo enconters->encounters

IPython/core/application.py

@@ -139,7 +139,7 b' class BaseIPythonApplication(Application):'
         """)
     
     verbose_crash = Bool(False, config=True,
-        help="""Create a massive crash report when IPython enconters what may be an
+        help="""Create a massive crash report when IPython encounters what may be an
         internal error.  The default is to append a short message to the
         usual traceback""")