validate: fix typos (#999)

Author: WineChord

validate/validate.proto

@@ -534,7 +534,7 @@ message StringRules {
     // at a maximum
     optional uint64 max_bytes = 5;
 
-    // Pattern specifes that this field must match against the specified
+    // Pattern specifies that this field must match against the specified
     // regular expression (RE2 syntax). The included expression should elide
     // any delimiters.
     optional string pattern  = 6;
@@ -646,7 +646,7 @@ message BytesRules {
     // at a maximum
     optional uint64 max_len = 3;
 
-    // Pattern specifes that this field must match against the specified
+    // Pattern specifies that this field must match against the specified
     // regular expression (RE2 syntax). The included expression should elide
     // any delimiters.
     optional string pattern  = 4;
@@ -732,11 +732,11 @@ message RepeatedRules {
     optional uint64 max_items = 2;
 
     // Unique specifies that all elements in this field must be unique. This
-    // contraint is only applicable to scalar and enum types (messages are not
+    // constraint is only applicable to scalar and enum types (messages are not
     // supported).
     optional bool   unique    = 3;
 
-    // Items specifies the contraints to be applied to each item in the field.
+    // Items specifies the constraints to be applied to each item in the field.
     // Repeated message fields will still execute validation against each item
     // unless skip is specified here.
     optional FieldRules items = 4;