fluidsynth: update SRC_URI to remove non-existing 2.1.x branch

Remove branch 2.1.x from SRC_URI as fluidsynth github removed the branch.
The SRCREV is on master branch

Signed-off-by: Kartikey Rameshbhai Parmar <kartikey.rameshbhai.parmar@intel.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
(cherry picked from commit 555b90779f6d86f7df05604f474323d9aef96886)
[AK: Minor clean for gatesgarth context]
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-multimedia/recipes-multimedia/fluidsynth/fluidsynth.inc

@@ -4,7 +4,7 @@ SECTION = "libs/multimedia"
 LICENSE = "LGPL-2.1"
 LIC_FILES_CHKSUM = "file://LICENSE;md5=fc178bcd425090939a8b634d1d6a9594"
 
-SRC_URI = "git://github.com/FluidSynth/fluidsynth.git;branch=2.1.x"
+SRC_URI = "git://github.com/FluidSynth/fluidsynth.git"
 SRCREV = "6776569abe9a885bcec14141692fa93c0568d51c"
 S = "${WORKDIR}/git"
 PV = "2.1.5"