sdist build: (minor) exclude more stuff from tar.gz, rm git clean log

The `git clean --dry-run` became redundant with "fresh clone" builds.
The new exclude in MANIFEST.in should not affect production builds (also due to fresh clone),
but they are nice when building from dirty local dir.

MANIFEST.in

@@ -17,8 +17,11 @@ graft contrib/udev
 
 exclude electrum/*.so
 exclude electrum/*.so.0
+exclude electrum/*.dll
+exclude electrum/*.dylib
 
 global-exclude __pycache__
 global-exclude *.py[co~]
 global-exclude *.py.orig
 global-exclude *.py.rej
+global-exclude .git

contrib/build-linux/sdist/make_tgz

@@ -33,12 +33,8 @@ git submodule update --init
 (
     cd "$ROOT_FOLDER"
 
-    echo "'git clean -fd' would delete the following files: >>>"
-    git clean -fd --dry-run
-    echo "<<<"
-
     # we could build the kivy atlas potentially?
-    #(cd electrum/gui/kivy/; make theming) || echo "building kivy atlas failed! skipping."
+    #(cd contrib/android/; make theming) || echo "building kivy atlas failed! skipping."
 
     find -exec touch -h -d '2000-11-11T11:11:11+00:00' {} +