Remove the jQuery submodule

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/src/third-party/jquery b/src/third-party/jquery
deleted file mode 160000 (submodule)
index 00c060d..0000000
--- a/src/third-party/jquery
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 00c060d1619d472a2d8c5b104ed76fa3afc2ce97