Updated README.md file to reflect current repository state

Author: mluis1

README.md

@@ -24,7 +24,7 @@ This project has 2 active branches in place.
 | ------------- |:-------------:|:---------:|:---------:|:---------:|:--------------|
 | | [1.0.4](https://lora-alliance.org/resource-hub/lorawan-104-specification-package) | [2-1.0.1](https://lora-alliance.org/sites/default/files/2020-02/rp_2-1.0.1.pdf) | [v4.5.1](https://github.com/Lora-net/LoRaMac-node/releases/tag/v4.5.1) | A/B/C | LoRaWAN L2 1.0.4 - **_Released_** |
 | | [1.0.3](https://lora-alliance.org/resource-hub/lorawanr-specification-v103) | [v1.0.3revA](https://www.lora-alliance.org/resource-hub/lorawanr-regional-parameters-v103reva) | [v4.4.7](https://github.com/Lora-net/LoRaMac-node/releases/tag/v4.4.7) | A/B/C | LoRaWAN L2 1.0.3 - **_Released_ (last release based on 1.0.3)** |
-| [master](https://github.com/Lora-net/LoRaMac-node/tree/master) | [1.0.4](https://lora-alliance.org/resource-hub/lorawan-104-specification-package) | [2-1.0.1](https://lora-alliance.org/sites/default/files/2020-02/rp_2-1.0.1.pdf) | [v4.5.1](https://github.com/Lora-net/LoRaMac-node/releases/tag/v4.5.1) | A/B/C |  LoRaWAN L2 1.0.4 |
+| [master](https://github.com/Lora-net/LoRaMac-node/tree/master) | [1.0.4](https://lora-alliance.org/resource-hub/lorawan-104-specification-package) | [2-1.0.1](https://lora-alliance.org/sites/default/files/2020-02/rp_2-1.0.1.pdf) | [M4.5.2](https://github.com/Lora-net/LoRaMac-node/milestone/9) | A/B/C |  LoRaWAN L2 1.0.4 |
 | [develop](https://github.com/Lora-net/LoRaMac-node/tree/develop) | [1.0.4](https://lora-alliance.org/resource-hub/lorawan-104-specification-package) / [1.1.1](https://lora-alliance.org/resource-hub/lorawanr-specification-v11) | [2-1.0.1](https://lora-alliance.org/sites/default/files/2020-02/rp_2-1.0.1.pdf) | [M 4.6.0](https://github.com/Lora-net/LoRaMac-node/milestone/3) | A/B/C |  LoRaWAN L2 1.0.4 / 1.1.1 |
 
 This project fully implements ClassA, ClassB and ClassC end-device classes and it also provides SX1272/73, SX1276/77/78/79, SX1261/2 and LR1110 radio drivers.