revise wording to avoid confusion for non-native English speakers

(second occurance of the same wording)

Doc/tut/tut.tex

@@ -750,7 +750,7 @@ For example:
 'p'
 >>> word[-2:]    # The last two characters
 'pA'
->>> word[:-2]    # All but the last two characters
+>>> word[:-2]    # Everything except the last two characters
 'Hel'
 \end{verbatim}