fix camera port detection (#99)

cameras.sh

@@ -221,7 +221,7 @@ add_camera() {
     fi
     
     
-    CAMPORT=$(tail -1 /etc/octoprint_cameras 2>/dev/null | sed -n -e 's/^.*\(port:\) \(.*\)/\2/p')
+    CAMPORT=$(tail -1 /etc/octoprint_cameras 2>/dev/null | sed -n -e 's/^.*port:\([[:graph:]]*\) \(.*\)/\1/p')
     
     if [ -z "$CAMPORT" ]; then
         CAMPORT=8000