Change variable name and add nil guard

Author: nk-ty

README.md

@@ -155,7 +155,7 @@ cases:
       - proc: open page
         exec:
           operate: go
-          url: <%= ENV['FQDN'] %>/results # Using erb notation to get environment variable
+          url: <%= ENV['BASE_FQDN'] %>/results # Using erb notation to get environment variable
       - proc: element click
         exec:
           operate: click
@@ -224,7 +224,7 @@ cases:
     desc: status check for detail page
     urls:
         - https://example.com/detail/1
-        - <%= ENV['FQDN'] %>/detail/2 # Using erb notation to get environment variable
+        - <%= ENV['BASE_FQDN'] %>/detail/2 # Using erb notation to get environment variable
 ```
 
 # Development

exe/bucky

@@ -135,7 +135,7 @@ def setup_test_cond(test_cond)
   %i[suite_name case label xlabel device].each do |k|
     test_cond[k] = test_cond[k].split(',') unless test_cond[k].nil?
   end
-  test_cond[:base_fqdn] = ENV['BUCKY_FQDN']
+  test_cond[:base_fqdn] = ENV['BASE_FQDN'] ||= ''
   test_cond
 end