fix typo

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/annotation/AbstractBatchConfiguration.java

@@ -105,7 +105,7 @@ public abstract class AbstractBatchConfiguration implements ImportAware {
 				this.configurer = configurer;
 				return configurer;
 			} else {
-				throw new IllegalStateException("To use the default BatchConfigurer the context must contain no more than" +
+				throw new IllegalStateException("To use the default BatchConfigurer the context must contain no more than " +
 														"one DataSource, found " + dataSources.size());
 			}
 		}