ipahost: fix adding host for servers without DNS configuration.

When using ipahost module with servers where DNS was not configured
it failed to add hosts due to an exception raised on `dnsrecord_show`
that was not being correctly handled.

As the exception was being handled twice, the This patch simply removes
one of the handlers, allowing the exception to propagate to the caller,
where it is handled.

Fixes issue #434.

plugins/modules/ipahost.py

@@ -439,6 +439,12 @@ def find_host(module, name):
 
 
 def find_dnsrecord(module, name):
+    """
+    Search for a DNS record.
+
+    This function may raise ipalib_errors.NotFound in some cases,
+    and it should be handled by the caller.
+    """
     domain_name = name[name.find(".")+1:]
     host_name = name[:name.find(".")]
 
@@ -447,14 +453,8 @@ def find_dnsrecord(module, name):
         "idnsname": to_text(host_name)
     }
 
-    try:
+    _result = api_command(module, "dnsrecord_show", to_text(domain_name),
-        _result = api_command(module, "dnsrecord_show", to_text(domain_name),
+                          _args)
-                              _args)
-    except ipalib_errors.NotFound as e:
-        msg = str(e)
-        if "record not found" in msg or "zone not found" in msg:
-            return None
-        module.fail_json(msg="dnsrecord_show failed: %s" % msg)
 
     return _result["result"]
 
@@ -876,8 +876,11 @@ def main():
                 msg = str(e)
                 dns_not_configured = "DNS is not configured" in msg
                 dns_zone_not_found = "DNS zone not found" in msg
-                if ip_address is None and (
+                dns_res_not_found = "DNS resource record not found" in msg
-                    dns_not_configured or dns_zone_not_found
+                if (
+                    dns_res_not_found
+                    or ip_address is None
+                    and (dns_not_configured or dns_zone_not_found)
                 ):
                     # IP address(es) not given and no DNS support in IPA
                     # -> Ignore failure