Fix URL of public key

Author: sgerrand

README.md

@@ -18,7 +18,7 @@ The current installation method for these packages is to pull them in using
 `wget` or `curl` and install the local file with `apk`:
 
     apk --no-cache add ca-certificates wget
-    wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand/alpine-pkg-php5-imagick/master/sgerrand.rsa.pub
+    wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub
     wget https://github.com/sgerrand/alpine-pkg-php5-imagick/releases/download/3.4.4-r0/php5-imagick-3.4.3-r0.apk
     apk add php5-imagick-3.4.4-r0.apk