recipes: Drop remaining PR values from recipes

* as oe-core did in:
  https://git.openembedded.org/openembedded-core/commit/?id=d4c346e8ab

* when people are have to maintain own PRs for recipes in oe-core, they
  might add them for meta-oe recipes at the same time when upgrading
  to next LTS

Signed-off-by: Martin Jansa <martin.jansa@gmail.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-networking/recipes-protocols/frr/frr_9.1.bb

@@ -9,7 +9,6 @@ LICENSE = "GPL-2.0-only & LGPL-2.1-only"
 LIC_FILES_CHKSUM = "file://doc/licenses/GPL-2.0;md5=b234ee4d69f5fce4486a80fdaf4a4263 \
                     file://doc/licenses/LGPL-2.1;md5=4fbd65380cdd255951079008b364516c"
 
-PR = "r1"
 
 SRC_URI = "git://github.com/FRRouting/frr.git;protocol=https;branch=stable/9.1 \
            file://frr.pam \

meta-networking/recipes-protocols/rp-pppoe/rp-pppoe_3.15.bb

@@ -4,7 +4,6 @@ SECTION = "net"
 LICENSE = "GPL-2.0-only"
 LIC_FILES_CHKSUM = "file://doc/LICENSE;md5=a194eaefae2be54ee3221339b10d0581"
 
-PR = "r11"
 
 SRC_URI = "https://dianne.skoll.ca/projects/rp-pppoe/download/OLD/rp-pppoe-${PV}.tar.gz \
            file://top-autoconf.patch \

meta-networking/recipes-protocols/zeroconf/zeroconf_0.9.bb

@@ -13,7 +13,6 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=4325afd396febcb659c36b49533135d4 \
                     file://zeroconf.c;beginline=1;endline=13;md5=a5bada96e1e34b08eb7446b28e2630b2"
 SECTION = "net"
 
-PR = "r1"
 
 SRC_URI = "http://www.progsoc.org/~wildfire/zeroconf/download/${BPN}-${PV}.tar.gz \
            file://compilefix.patch \

meta-networking/recipes-support/netcat/netcat_0.7.1.bb

@@ -2,7 +2,6 @@ require netcat.inc
 LICENSE = "GPL-2.0-only"
 LIC_FILES_CHKSUM = "file://COPYING;md5=94d55d512a9ba36caa9b7df079bae19f"
 
-PR = "r3"
 
 SRC_URI = "${SOURCEFORGE_MIRROR}/netcat/netcat-${PV}.tar.bz2 \
            file://obsolete_autoconf_macros.patch \