[range.utility.conv.to] Remove erroneous "if" introduced in LWG3733.

Author: burblebee

source/ranges.tex

@@ -2298,7 +2298,7 @@
 \item
 \tcode{\libconcept{common_range}<R>} is \tcode{true},
 \item
-if the \grammarterm{qualified-id}
+the \grammarterm{qualified-id}
 \tcode{iterator_traits<iterator_t<R>>::iterator_category}
 is valid and denotes a type that models
 \tcode{\libconcept{derived_from}<input_iterator_tag>}, and