fix transport header error with some Hikvision cameras

fixes 'invalid transport header: encoding/hex: invalid byte: U+0020 ' ''.

go.mod

@@ -3,7 +3,7 @@ module github.com/aler9/rtsp-simple-server
 go 1.17
 
 require (
-	github.com/aler9/gortsplib v0.0.0-20211210220138-165b34709034
+	github.com/aler9/gortsplib v0.0.0-20220105105403-50f19e665335
 	github.com/asticode/go-astits v1.10.0
 	github.com/fsnotify/fsnotify v1.4.9
 	github.com/gin-gonic/gin v1.7.2

go.sum

@@ -2,8 +2,8 @@ github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 h1:JYp7IbQjafo
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d h1:UQZhZ2O0vMHr2cI+DC1Mbh0TJxzA3RcLoMsFw+aXw7E=
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d/go.mod h1:rBZYJk541a8SKzHPHnH3zbiI+7dagKZ0cgpgrD7Fyho=
-github.com/aler9/gortsplib v0.0.0-20211210220138-165b34709034 h1:vbLCZi2tonu2eF4j2MxPYCHIA6qu4owgEyxG5ED/y2k=
-github.com/aler9/gortsplib v0.0.0-20211210220138-165b34709034/go.mod h1:fyQrQyHo8QvdR/h357tkv1g36VesZlzEPsdAu2VrHHc=
+github.com/aler9/gortsplib v0.0.0-20220105105403-50f19e665335 h1:BiH/6vNvJOSbxcEb0ghAaeXAfCXYjFgwG0uGbkRsIdI=
+github.com/aler9/gortsplib v0.0.0-20220105105403-50f19e665335/go.mod h1:fyQrQyHo8QvdR/h357tkv1g36VesZlzEPsdAu2VrHHc=
 github.com/aler9/rtmp v0.0.0-20210403095203-3be4a5535927 h1:95mXJ5fUCYpBRdSOnLAQAdJHHKxxxJrVCiaqDi965YQ=
 github.com/aler9/rtmp v0.0.0-20210403095203-3be4a5535927/go.mod h1:vzuE21rowz+lT1NGsWbreIvYulgBpCGnQyeTyFblUHc=
 github.com/asticode/go-astikit v0.20.0 h1:+7N+J4E4lWx2QOkRdOf6DafWJMv6O4RRfgClwQokrH8=