remove outdated workaround for OpenBSD fclose() calling close()

Test program:
```c
 #include <sys/utsname.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <fcntl.h>

static int closed;

int
close(int unused)
{
	closed = 1;
	return 0;
}

int main()
{
	struct utsname os;
	int fd;
	FILE *file;
	char *closed_str[] = {" not", ""};
	uname(&os);
	if ((fd = open("/dev/null", O_RDONLY)) == -1)
		return 1;
	if ((file = fdopen(fd, "rb")) == NULL)
		return 1;
	printf("Operating system: %s/%s %s %s\n", os.sysname, os.machine,
	    os.release, os.version);
	closed = 0;
	fclose(stdin);
	printf("close()%s called on stdin\n", closed_str[closed]);
	closed = 0;
	fclose(file);
	printf("close()%s called on nonstd stream\n", closed_str[closed]);
}
```

Output:
```console
$ ./a.out
Operating system: OpenBSD/amd64 7.4 GENERIC.MP#0
close() not called on stdin
close() not called on nonstd stream
```

Author: guijan

configure

@@ -220,9 +220,6 @@ check_define __FreeBSD__ && bsd_detected=true
 check_define __OpenBSD__ && {
 bsd_detected=true
 echo "CFLAGS+=-DIS_OPENBSD">>config.mak
-check_compile_run 'whether OpenBSDs fclose() (illegally) calls close()' \
-'#include <stdio.h>\n#include<stdlib.h>\nint close(int x){exit(0);}int main(){fclose(stdin);return 1;}' && \
-OUR_CPPFLAGS="$OUR_CPPFLAGS -DBROKEN_FCLOSE"
 }
 check_define __sun && check_define __SVR4 && solaris_detected=true
 check_define __HAIKU__ && haiku_detected=true

src/libproxychains.c

@@ -115,7 +115,7 @@ typedef struct {
 	unsigned int first, last, flags;
 } close_range_args_t;
 
-/* If there is some `close` or `close_range` system call before do_init, 
+/* If there is some `close` or `close_range` system call before do_init,
    we buffer it, and actually execute them in do_init. */
 static int close_fds[16];
 static int close_fds_cnt = 0;
@@ -560,9 +560,7 @@ static void get_chain_data(proxy_data * pd, unsigned int *proxy_count, chain_typ
 			}
 		}
 	}
-#ifndef BROKEN_FCLOSE
 	fclose(file);
-#endif
 	if(!count) {
 		fprintf(stderr, "error: no valid proxy found in config\n");
 		exit(1);
@@ -639,7 +637,7 @@ HOOKFUNC(int, close_range, unsigned first, unsigned last, int flags) {
 	int protected_fds[] = {req_pipefd[0], req_pipefd[1], resp_pipefd[0], resp_pipefd[1]};
 	intsort(protected_fds, 4);
 	/* We are skipping protected_fds while calling true_close_range()
-	 * If protected_fds cut the range into some sub-ranges, we close sub-ranges BEFORE cut point in the loop. 
+	 * If protected_fds cut the range into some sub-ranges, we close sub-ranges BEFORE cut point in the loop.
 	 * [first, cut1-1] , [cut1+1, cut2-1] , [cut2+1, cut3-1]
 	 * Finally, we delete the remaining sub-range, outside the loop. [cut3+1, tail]
 	 */