Extensions recode and imap can't be loaded together, but they can be build
together, and that's what we want.

Source: https://src.fedoraproject.org/cgit/rpms/php.git/tree/php-5.3.0-recode.patch?h=f26
--- a/ext/recode/config9.m4
+++ b/ext/recode/config9.m4
@@ -4,13 +4,6 @@ dnl
 
 dnl Check for extensions with which Recode can not work
 if test "$PHP_RECODE" != "no"; then
-  test "$PHP_IMAP"  != "no" && recode_conflict="$recode_conflict imap"
-
-  if test -n "$MYSQL_LIBNAME"; then
-    PHP_CHECK_LIBRARY($MYSQL_LIBNAME, hash_insert, [
-      recode_conflict="$recode_conflict mysql"
-    ])
-  fi
 
   if test -n "$recode_conflict"; then
     AC_MSG_ERROR([recode extension can not be configured together with:$recode_conflict])