Align MANIFEST.MF plugin name with repo and Bazel name

This plugin is named 'delete-project' in its Gerrit repo and Bazel
build file. Align the MANIFEST.MF name with the correct one, including
the hyphen '-'.

Change-Id: I4a6a00f78013cbb4d4168ea9a0ee8fd8cc1bece3
diff --git a/BUILD b/BUILD
index 9213a7c..9da8336 100644
--- a/BUILD
+++ b/BUILD
@@ -10,7 +10,7 @@
     name = "delete-project",
     srcs = glob(["src/main/java/**/*.java"]),
     manifest_entries = [
-        "Gerrit-PluginName: deleteproject",
+        "Gerrit-PluginName: delete-project",
         "Gerrit-Module: com.googlesource.gerrit.plugins.deleteproject.Module",
         "Gerrit-HttpModule: com.googlesource.gerrit.plugins.deleteproject.HttpModule",
         "Gerrit-SshModule: com.googlesource.gerrit.plugins.deleteproject.SshModule",