Fixing property names in mapping document. Fixes elastic#860

Author: jbaiera

docs/src/reference/asciidoc/core/mapping.adoc

@@ -52,7 +52,7 @@ Note that typically handling of these types poses no issues for the user whether
 [[mapping-multi-values]]
 === Handling array/multi-values fields
 
-{es} treats fields with single or multi-values the same; in fact, the mapping provides no information about this. As a client, it means one cannot tell whether a field is single-valued or not until is actually being read. In most cases this is not an issue and {eh} automatically creates the necessary list/array on the fly. However in environments with strict schema such as Spark SQL, changing a field actual value from its declared type is not allowed. Worse yet, this information needs to be available even before reading the data. Since the mapping is not conclusive enough, {eh} allows the user to specify the extra information through <<cfg-field-info, field information>>, specifically +es.field.read.as.array.include+ and +es.field.read.as.array.include+.
+{es} treats fields with single or multi-values the same; in fact, the mapping provides no information about this. As a client, it means one cannot tell whether a field is single-valued or not until is actually being read. In most cases this is not an issue and {eh} automatically creates the necessary list/array on the fly. However in environments with strict schema such as Spark SQL, changing a field actual value from its declared type is not allowed. Worse yet, this information needs to be available even before reading the data. Since the mapping is not conclusive enough, {eh} allows the user to specify the extra information through <<cfg-field-info, field information>>, specifically +es.read.field.as.array.include+ and +es.read.field.as.array.exclude+.
 
 [float]
 === Automatic mapping