[JENKINS-17333] translated "Configure Global Security" (es)

"Manage Credentials" is defined in credentials-plugin. I will create a
pull request for that as well.

core/src/main/resources/hudson/security/Messages_es.properties

@@ -20,6 +20,9 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
+GlobalSecurityConfiguration.DisplayName=Configuraci\u00F3n global de la seguridad
+GlobalSecurityConfiguration.Description=Seguridad en Jenkins. \
+  Define qui\u00E9n tiene acceso al sistema (autenticaci\u00F3n) y qu\u00E9 puede hacer (autorizaci\u00F3n)
 GlobalMatrixAuthorizationStrategy.DisplayName=Configuracin de seguridad
 
 LegacyAuthorizationStrategy.DisplayName=Modo ''legacy''