travis-ci: Cosmetic changes

Use two spaces for indentation.

.travis.yml

@@ -1,22 +1,22 @@
 language: c
 
 before_install:
-    - sudo apt-get update -qq
+  - sudo apt-get update -qq
 
 install:
-    - sudo apt-get install -qq --no-install-recommends perl autotools-dev libdbi-dev libldap2-dev libpq-dev libmysqlclient-dev libradiusclient-ng-dev libkrb5-dev libnet-snmp-perl procps mawk
-    - sudo apt-get install -qq --no-install-recommends autoconf automake
+  - sudo apt-get install -qq --no-install-recommends perl autotools-dev libdbi-dev libldap2-dev libpq-dev libmysqlclient-dev libradiusclient-ng-dev libkrb5-dev libnet-snmp-perl procps mawk
+  - sudo apt-get install -qq --no-install-recommends autoconf automake
 
 before_script:
-    - tools/setup
-    - ./configure
+  - tools/setup
+  - ./configure
 
 script:
-    - if [ "$COVERITY_SCAN_BRANCH" != 1 ]; then make; fi
+  - if [ "$COVERITY_SCAN_BRANCH" != 1 ]; then make; fi
 
 compiler:
-    - clang
-    - gcc
+  - clang
+  - gcc
 
 notifications:
   irc: