Use upstream plexus-compiler-eclipse

Relevant bugs have since been fixed

pom.xml

@@ -91,26 +91,6 @@
         </dependency>
     </dependencies>
 
-    <repositories>
-        <!--
-            If you are a plugin developer, please use https://hub.spigotmc.org/nexus/content/repositories/snapshots/
-            as your repository URL. This will ensure only Bukkit / Spigot-API are pulled from our Maven repository.
-
-            Please see https://www.spigotmc.org/go/maven for more information.
-        -->
-        <repository>
-            <id>spigotmc-public</id>
-            <url>https://hub.spigotmc.org/nexus/content/groups/public/</url>
-        </repository>
-    </repositories>
-
-    <pluginRepositories>
-        <pluginRepository>
-            <id>spigotmc-public</id>
-            <url>https://hub.spigotmc.org/nexus/content/groups/public/</url>
-        </pluginRepository>
-    </pluginRepositories>
-
     <!-- This builds a completely 'ready to start' jar with all dependencies inside -->
     <build>
         <plugins>
@@ -255,11 +235,10 @@
                     <compilerId>eclipse</compilerId>
                 </configuration>
                 <dependencies>
-                    <!-- we need our custom version as it fixes some bugs on case sensitive file systems -->
                     <dependency>
                         <groupId>org.codehaus.plexus</groupId>
                         <artifactId>plexus-compiler-eclipse</artifactId>
-                        <version>2.8.5-spigotmc</version>
+                        <version>2.8.8</version>
                     </dependency>
                     <dependency>
                         <groupId>org.eclipse.jdt</groupId>