fix a prompt of RACE dataset (#841)

Author: xuanqing94

promptsource/templates/race/all/templates.yaml

@@ -103,7 +103,7 @@ templates:
 
       Question: {{question}}
 
-      Yes or no, is the answer "{{ [options.0,options.1,options.2,options.3][{"A":0,"B":1,"C":2,"D":3}[answer]]
+      Yes or no, is the answer "{{ [options.0,options.1,options.2,options.3][{"A":0,"B":1,"C":2,"D":3}[candidate]]
       }}"?
 
       |||

promptsource/templates/race/high/templates.yaml

@@ -10,7 +10,7 @@ templates:
 
       Question: {{question}}
 
-      Yes or no, is the answer "{{ [options.0,options.1,options.2,options.3][{"A":0,"B":1,"C":2,"D":3}[answer]]
+      Yes or no, is the answer "{{ [options.0,options.1,options.2,options.3][{"A":0,"B":1,"C":2,"D":3}[candidate]]
       }}"?
 
       |||

promptsource/templates/race/middle/templates.yaml

@@ -62,7 +62,7 @@ templates:
 
       Question: {{question}}
 
-      Yes or no, is the answer "{{ [options.0,options.1,options.2,options.3][{"A":0,"B":1,"C":2,"D":3}[answer]]
+      Yes or no, is the answer "{{ [options.0,options.1,options.2,options.3][{"A":0,"B":1,"C":2,"D":3}[candidate]]
       }}"?
 
       |||