osmo-e1-hardware: Fix missing PKG_CONFIG_PATH directory

otherwise we'll get:

make: Entering directory '/build/doc/manuals'
Package osmo-gsm-manuals was not found in the pkg-config search path.
Perhaps you should add the directory containing `osmo-gsm-manuals.pc'
to the PKG_CONFIG_PATH environment variable
No package 'osmo-gsm-manuals' found

Change-Id: I9f3d6e74be9e0fe31a2ee7aad9869ed7568ff6dd
diff --git a/contrib/jenkins.sh b/contrib/jenkins.sh
index b788540..39d7f4c 100755
--- a/contrib/jenkins.sh
+++ b/contrib/jenkins.sh
@@ -29,6 +29,10 @@
 inst="$deps/install"
 export deps inst
 
+export PKG_CONFIG_PATH="$inst/lib/pkgconfig:$PKG_CONFIG_PATH"
+export LD_LIBRARY_PATH="$inst/lib"
+export PATH="$inst/bin:$PATH"
+
 osmo-clean-workspace.sh
 
 mkdir "$deps" || true