[alg.replace] Fixed transcription error in template head

Author: tkoeppe

source/algorithms.tex

@@ -7196,7 +7196,7 @@
   I ranges::replace_if(Ep&& exec, I first, S last, Pred pred,
                        const T& new_value, Proj proj = {});
 template<@\exposconcept{execution-policy}@ Ep, @\exposconcept{sized-random-access-range}@ R, class Proj = identity,
-         class T = projected_value_t<I, Proj>,
+         class T = projected_value_t<iterator_t<R>, Proj>,
          @\libconcept{indirect_unary_predicate}@<projected<iterator_t<R>, Proj>> Pred>
   requires @\libconcept{indirectly_writable}@<iterator_t<R>, const T&>
   borrowed_iterator_t<R>