[except.terminate] Clarify evaluation of a contract

Author: jensmaurer

source/exceptions.tex

@@ -1031,7 +1031,7 @@
 exits via an exception\iref{support.start.term}, or
 
 \item%
-when evaluation of a predicate\iref{dcl.attr.contract}
+when evaluation of the predicate of a contract\iref{dcl.attr.contract}
 exits via an exception, or
 
 \item%