Fix help message for subnetpool default-quota value

Default pre-project quota is the number of IP addresses that can be
allocated from the subnet pool. For example, with a quota of 128,
I might get a 64 addresses subnet1, and 16 addresses subnet2,
and still have room to allocate 48 more addresses in the future.

Change-Id: Ia0ba827790b190647aed990e47347560fc9e9f0c

Author: Wenran Xiao

doc/source/cli/command-objects/subnet-pool.rst

@@ -77,8 +77,8 @@ Create subnet pool
 
 .. option:: --default-quota <num-ip-addresses>
 
-    Set default quota for subnet pool as the number of
-    IP addresses allowed in a subnet
+    Set default per-project quota for this subnet pool as the number of
+    IP addresses that can be allocated from the subnet pool
 
 .. option:: --tag <tag>
 
@@ -250,8 +250,8 @@ Set subnet pool properties
 
 .. option:: --default-quota <num-ip-addresses>
 
-    Set default quota for subnet pool as the number of
-    IP addresses allowed in a subnet
+    Set default per-project quota for this subnet pool as the number of
+    IP addresses that can be allocated from the subnet pool
 
 .. option:: --tag <tag>
 

openstackclient/network/v2/subnet_pool.py

@@ -191,8 +191,9 @@ def get_parser(self, prog_name):
             '--default-quota',
             type=int,
             metavar='<num-ip-addresses>',
-            help=_("Set default quota for subnet pool as the number of"
-                   "IP addresses allowed in a subnet")),
+            help=_("Set default per-project quota for this subnet pool "
+                   "as the number of IP addresses that can be allocated "
+                   "from the subnet pool")),
         _tag.add_tag_option_to_parser_for_create(parser, _('subnet pool'))
         return parser
 
@@ -389,8 +390,9 @@ def get_parser(self, prog_name):
             '--default-quota',
             type=int,
             metavar='<num-ip-addresses>',
-            help=_("Set default quota for subnet pool as the number of"
-                   "IP addresses allowed in a subnet")),
+            help=_("Set default per-project quota for this subnet pool "
+                   "as the number of IP addresses that can be allocated "
+                   "from the subnet pool")),
         _tag.add_tag_option_to_parser_for_set(parser, _('subnet pool'))
 
         return parser