[futures.{unique,shared}.future] Fix hyphenation of "{copy,move} assignment"

Author: Eisenwave

source/threads.tex

@@ -10575,7 +10575,7 @@
 
 \pnum
 The effect of calling any member function other than the destructor, the
-move-assignment operator, \tcode{share}, or \tcode{valid} on a \tcode{future} object for which
+move assignment operator, \tcode{share}, or \tcode{valid} on a \tcode{future} object for which
 \tcode{valid() == false}
 is undefined.
 \begin{note}
@@ -10882,7 +10882,7 @@
 
 \pnum
 The effect of calling any member function other than the destructor,
-the move-assignment operator, the copy-assignment operator, or
+the move assignment operator, the copy assignment operator, or
 \tcode{valid()} on a \tcode{shared_future} object for which \tcode{valid() == false} is undefined.
 \begin{note}
 It is valid to copy or move from a \tcode{shared_future}