library: changing P_G_SZ from 20 to 33

Nowadays the usernames can be 32 characters long
(typically OpenShift usernames use the whole length)
and the old limit was preventing us from processing
them correctly.
The macro change affects the proc_t structure size.

proc/pwcache.h

@@ -7,7 +7,7 @@
 EXTERN_C_BEGIN
 
 // used in pwcache and in readproc to set size of username or groupname
-#define P_G_SZ 20
+#define P_G_SZ 33
 
 extern char *user_from_uid(uid_t uid);
 extern char *group_from_gid(gid_t gid);