Include strings.h which is needed for strcasemp. Some systems declare them

in string.h, but it should be possible to include both.

clients/lcdexec/lcdexec.c

@@ -14,6 +14,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>
+#include <strings.h>
 #include <errno.h>
 #include <sys/utsname.h>
 #include <signal.h>