Added explicit include of time.h.

Most of the systems have it included due to namespace pollution, but
relying on this is a bad idea.  Explicit include is required for at least
Debian GNU/Hurd.

src/os/unix/ngx_freebsd_config.h

diff --git a/src/os/unix/ngx_freebsd_config.h b/src/os/unix/ngx_freebsd_config.h
index 460581a..5b3ff27 100644
--- a/src/os/unix/ngx_freebsd_config.h
+++ b/src/os/unix/ngx_freebsd_config.h
@@ -23,6 +23,7 @@
 #include <grp.h>
 #include <dirent.h>
 #include <glob.h>
+#include <time.h>
 #include <sys/param.h>          /* ALIGN() */
 #include <sys/mount.h>          /* statfs() */
 

src/os/unix/ngx_posix_config.h

diff --git a/src/os/unix/ngx_posix_config.h b/src/os/unix/ngx_posix_config.h
index a0a2c8c..4d432a7 100644
--- a/src/os/unix/ngx_posix_config.h
+++ b/src/os/unix/ngx_posix_config.h
@@ -45,6 +45,7 @@
 #include <grp.h>
 #include <dirent.h>
 #include <glob.h>
+#include <time.h>
 #if (NGX_HAVE_SYS_PARAM_H)
 #include <sys/param.h>          /* statfs() */
 #endif

src/os/unix/ngx_solaris_config.h

diff --git a/src/os/unix/ngx_solaris_config.h b/src/os/unix/ngx_solaris_config.h
index 8a86fe6..e664ba8 100644
--- a/src/os/unix/ngx_solaris_config.h
+++ b/src/os/unix/ngx_solaris_config.h
@@ -29,6 +29,7 @@
 #include <grp.h>
 #include <dirent.h>
 #include <glob.h>
+#include <time.h>
 #include <sys/statvfs.h>        /* statvfs() */
 
 #include <sys/filio.h>          /* FIONBIO */