master-builds/gerrit: remove redundant GTP="$GTP"

Variables for axes are already exported as environment variables.
Change 'GTP="$GTP" ./contrib/jenkins.sh' to './contrib/jenkins.sh' to
avoid confusion when introducing other variables.

Change-Id: I9238da3dd3c4461f82dc7c792f886177399be3dc

jobs/gerrit-verifications.yml

@@ -89,7 +89,7 @@
       - openggsn:
           a1_name: GTP
           a1: !!python/tuple [--enable-gtp-linux,--disable-gtp-linux]
-          cmd: GTP="$GTP" ./contrib/jenkins.sh
+          cmd: ./contrib/jenkins.sh
 
       - osmo-bsc:
           concurrent: true
@@ -126,7 +126,7 @@
       - osmo-ggsn:
           a1_name: GTP
           a1: !!python/tuple [--enable-gtp-linux,--disable-gtp-linux]
-          cmd: GTP="$GTP" ./contrib/jenkins.sh
+          cmd: ./contrib/jenkins.sh
 
       - osmo-gsm-manuals
 

jobs/master-builds.yml

@@ -197,7 +197,7 @@
       - osmo-ggsn:
           a1_name: GTP
           a1: !!python/tuple [--enable-gtp-linux,--disable-gtp-linux]
-          cmd: GTP="$GTP" ./contrib/jenkins.sh --publish
+          cmd: ./contrib/jenkins.sh --publish
           trigger: master-osmo-sgsn
 
       - osmo-gmr: