logstash: fix missing package hooks

logstash packages were failing to run the pre/postInstall hooks, despite
running the install phase.

pkgs/tools/misc/logstash/6.x.nix

@@ -30,6 +30,7 @@ stdenv.mkDerivation rec {
   ];
 
   installPhase = ''
+    runHook preInstall
     mkdir -p $out
     cp -r {Gemfile*,modules,vendor,lib,bin,config,data,logstash-core,logstash-core-plugin-api} $out
 
@@ -41,6 +42,7 @@ stdenv.mkDerivation rec {
 
     wrapProgram $out/bin/logstash-plugin \
        --set JAVA_HOME "${jre}"
+    runHook postInstall
   '';
 
   meta = with stdenv.lib; {

pkgs/tools/misc/logstash/7.x.nix

@@ -30,6 +30,7 @@ stdenv.mkDerivation rec {
   ];
 
   installPhase = ''
+    runHook preInstall
     mkdir -p $out
     cp -r {Gemfile*,modules,vendor,lib,bin,config,data,logstash-core,logstash-core-plugin-api} $out
 
@@ -41,6 +42,7 @@ stdenv.mkDerivation rec {
 
     wrapProgram $out/bin/logstash-plugin \
        --set JAVA_HOME "${jre}"
+    runHook postInstall
   '';
 
   meta = with stdenv.lib; {

pkgs/tools/misc/logstash/contrib.nix

@@ -1,7 +1,7 @@
 { stdenv, lib, fetchzip }:
 
 # Note that plugins are supposed to be installed as:
-#   $path/logstash/{inputs,codecs,filters,outputs}/*.rb 
+#   $path/logstash/{inputs,codecs,filters,outputs}/*.rb
 stdenv.mkDerivation rec {
   version = "1.4.2";
   pname = "logstash-contrib";
@@ -17,8 +17,10 @@ stdenv.mkDerivation rec {
   dontPatchShebangs = true;
 
   installPhase = ''
+    runHook preInstall
     mkdir -p $out/logstash
     cp -r lib/* $out
+    runHook postInstall
   '';
 
   meta = with lib; {