Fix validity errors in file

Minor capitalisation issue and a couple of logic fails. Fortunately they didn't
affect anything but would have on clean servers.

tasks/install-shinken-packages.yml

@@ -6,22 +6,20 @@
     state: present
 
 - name: Install build dependencies for pycurl
-  when: shinken_install_from == "pip"
-  when: ansible_os_family == "Debian"
+  when: shinken_install_from == "pip" and ansible_os_family == "Debian"
   package:
     name: "{{ shinken_pycurl_build_deps }}"
     state: present
 
 
 - name: Install runtime dependencies where required
-  when: ansible_os_family == "Redhat"
+  when: ansible_os_family == "RedHat"
   package:
     name: redhat-lsb-core
     state: present
 
 - name: Install pycurl using pip
-  when: shinken_install_from == "pip"
-  when: ansible_os_family == "Debian"
+  when: shinken_install_from == "pip" and ansible_os_family == "Debian"
   pip: 
     name: pycurl
     version: 7.43.0