Fix broken links in 2019 blog posts

content/blog/2019/07/2019-07-30-plugin-management-tool-phase2-updates.adoc

@@ -12,7 +12,7 @@ author: stopalopa
 ---
 
 At end of the first link:https://summerofcode.withgoogle.com/[GSoC] phase, I
-link:/blog/2019/07/2019-07-02-plugin-management-tool-alpha-release.adoc[announced
+link:/blog/2019/07/plugin-management-tool-alpha-release/[announced
 the first alpha release] of the CLI tool and library that will help centralize
 plugin management and make plugin tooling easier.
 

content/blog/2019/08/2019-08-16-folder-auth-plugin.adoc

@@ -45,7 +45,7 @@ and assigned to multiple users.
 
 This plugin is designed to outperform Role Strategy Plugin in permission
 checks. The improvements were measured using the
-link:blog/2019/06/21/performance-testing-jenkins/[micro-benchmark framework]
+link:/blog/2019/06/21/performance-testing-jenkins/[micro-benchmark framework]
 I had created during the first phase of my GSoC project.
 Benchmarks for identical configurations for both plugin show that the
 permissions check are up to 934x faster for 500 global roles when compared to

content/blog/2019/08/2019-08-23-introducing-gitlab-branch-source-plugin.adoc

@@ -184,7 +184,7 @@ organizationFolder('GitLab Organization Folder') {
 }
 ----
 
-You can also use `JCasC` to directly create job from a Job DSL script. For example see the plugin link:https://github.com/jenkinsci/gitlab-branch-source-plugin/blob/develop/README.md[repository].
+You can also use `JCasC` to directly create job from a Job DSL script. For example see the plugin link:https://github.com/jenkinsci/gitlab-branch-source-plugin/blob/master/README.md[repository].
 
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