Change Number of UEs usage [#533]

- Set the number of UEs in units of AMF/MME instead of gNB/eNB.
- See default value as shown below
    Number of UEs per AMF/MME : 4,096
    Number of gNB/eNB per AMF/MME : 32

lib/core/ogs-core.h

@@ -86,14 +86,6 @@ typedef struct {
         int config_pool;
     } pkbuf;
 
-    struct {
-        int pool;
-    } socket;
-
-    struct {
-        int pool;
-    } timer;
-
     struct {
         int pool;
     } tlv;