Merge the separated link lines on service client

On current docstring of service clients, every link to API
reference is separated to 2 lines. That is unreadable on the
code and the documentation which is created from the docstring
also will be unreadablebecause of the separated link lines.

This patch merges the separated lines into a single line for the
readability.

Co-Authored-By: Shu Muto <shu-mutou@rf.jp.nec.com>
Co-Authored-By: Reedip <reedip.banerjee@nectechnologies.in>
Co-Authored-By: xu-haiwei <hai-xu@xr.jp.nec.com>
Change-Id: Ib1a4f2232dad8a2bc9d21a7c3509bc3b7bc0c827
diff --git a/tempest/lib/services/identity/v3/trusts_client.py b/tempest/lib/services/identity/v3/trusts_client.py
index e3d5a41..d113905 100644
--- a/tempest/lib/services/identity/v3/trusts_client.py
+++ b/tempest/lib/services/identity/v3/trusts_client.py
@@ -24,8 +24,9 @@
     def create_trust(self, **kwargs):
         """Creates a trust.
 
-        Available params: see http://developer.openstack.org/
-                              api-ref/identity/v3-ext/index.html#create-trust
+        For a full list of available parameters, please refer to the official
+        API reference:
+        http://developer.openstack.org/api-ref/identity/v3-ext/index.html#create-trust
         """
         post_body = json.dumps({'trust': kwargs})
         resp, body = self.post('OS-TRUST/trusts', post_body)
@@ -42,8 +43,9 @@
     def list_trusts(self, **params):
         """Returns trusts
 
-        Available params: see http://developer.openstack.org/
-                              api-ref/identity/v3-ext/index.html#list-trusts
+        For a full list of available parameters, please refer to the official
+        API reference:
+        http://developer.openstack.org/api-ref/identity/v3-ext/index.html#list-trusts
         """
         url = "OS-TRUST/trusts/"
         if params: