auth: mycrypt - include crypt.h

Fixes crypt usage on glibc-2.28

Reported by Reuben Farrelly
Patch provided by Thore Bödecker

configure.ac

@@ -315,7 +315,7 @@ AC_CHECK_HEADERS(strings.h stdint.h unistd.h dirent.h malloc.h \
   quota.h sys/fs/quota_common.h \
   mntent.h sys/mnttab.h sys/event.h sys/time.h sys/mkdev.h linux/dqblk_xfs.h \
   xfs/xqm.h execinfo.h ucontext.h malloc_np.h sys/utsname.h sys/vmount.h \
-  sys/utsname.h glob.h linux/falloc.h ucred.h sys/ucred.h)
+  sys/utsname.h glob.h linux/falloc.h ucred.h sys/ucred.h crypt.h)
 
 CC_CLANG
 AC_CC_PIE

src/auth/mycrypt.c

@@ -14,6 +14,9 @@
 #  define _XPG6 /* Some Solaris versions require this, some break with this */
 #endif
 #include <unistd.h>
+#ifdef HAVE_CRYPT_H
+# include <crypt.h>
+#endif
 
 #include "mycrypt.h"