readme: update version number in links to 1.10.4.1

(Though, it doesn't matter much for the thirdparty packages, as the contents are identical to 1.10.4)

README.md

@@ -24,7 +24,7 @@ Installing Panda3D
 ==================
 
 The latest Panda3D SDK can be downloaded from
-[this page](https://www.panda3d.org/download/sdk-1-10-4/).
+[this page](https://www.panda3d.org/download/sdk-1-10-4-1/).
 If you are familiar with installing Python packages, you can use
 the following comand:
 
@@ -64,8 +64,8 @@ depending on whether you are on a 32-bit or 64-bit system, or you can
 [click here](https://github.com/rdb/panda3d-thirdparty) for instructions on
 building them from source.
 
-https://www.panda3d.org/download/panda3d-1.10.4/panda3d-1.10.4-tools-win64.zip
-https://www.panda3d.org/download/panda3d-1.10.4/panda3d-1.10.4-tools-win32.zip
+https://www.panda3d.org/download/panda3d-1.10.4.1/panda3d-1.10.4.1-tools-win64.zip
+https://www.panda3d.org/download/panda3d-1.10.4.1/panda3d-1.10.4.1-tools-win32.zip
 
 After acquiring these dependencies, you may simply build Panda3D from the
 command prompt using the following command.  (Change `14.1` to `14` if you are
@@ -135,7 +135,7 @@ macOS
 -----
 
 On macOS, you will need to download a set of precompiled thirdparty packages in order to
-compile Panda3D, which can be acquired from [here](https://www.panda3d.org/download/panda3d-1.10.4/panda3d-1.10.4-tools-mac.tar.gz).
+compile Panda3D, which can be acquired from [here](https://www.panda3d.org/download/panda3d-1.10.4.1/panda3d-1.10.4.1-tools-mac.tar.gz).
 
 After placing the thirdparty directory inside the panda3d source directory,
 you may build Panda3D using a command like the following: