Make EL available to reactive web apps as it already is to servlet web apps

Closes gh-16596

spring-boot-project/spring-boot-starters/spring-boot-starter-reactor-netty/pom.xml

@@ -18,5 +18,9 @@
 			<groupId>io.projectreactor.netty</groupId>
 			<artifactId>reactor-netty</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.glassfish</groupId>
+			<artifactId>javax.el</artifactId>
+		</dependency>
 	</dependencies>
 </project>