Update io.projectreactor to 2020.0.19

Closes gh-11213

Author: rwinch

buildSrc/build.gradle

@@ -72,7 +72,7 @@ dependencies {
 implementation localGroovy()
 
 implementation 'io.github.gradle-nexus:publish-plugin:1.1.0'
-implementation 'io.projectreactor:reactor-core:3.4.17'
+implementation 'io.projectreactor:reactor-core:3.4.18'
 implementation 'gradle.plugin.org.gretty:gretty:3.0.1'
 implementation 'com.apollographql.apollo:apollo-runtime:2.4.5'
 implementation 'com.github.ben-manes:gradle-versions-plugin:0.38.0'

dependencies/spring-security-dependencies.gradle

@@ -8,7 +8,7 @@ javaPlatform {
 
 dependencies {
 api platform("org.springframework:spring-framework-bom:$springFrameworkVersion")
-api platform("io.projectreactor:reactor-bom:2020.0.18")
+api platform("io.projectreactor:reactor-bom:2020.0.19")
 api platform("io.rsocket:rsocket-bom:1.1.2")
 api platform("org.springframework.data:spring-data-bom:2021.0.10")
 api platform("org.jetbrains.kotlin:kotlin-bom:$kotlinVersion")