Fix seahub requirements

seafile-server.install

@@ -9,9 +9,10 @@ pre_install() {
     pip install python-dateutil
     pip install django-pipeline
     pip install "Django>=1.5.8,<1.6"
-    pip install "Djblets==0.6.14" --no-deps --allow-external Djblets --allow-unverified Djblets
+    pip install http://effbot.org/media/downloads/PIL-1.1.7.tar.gz
+    pip install "https://github.com/djblets/djblets/archive/release-0.6.14.zip#egg=Djblets"
     pip install "Pillow>=2.6.1,<3.0.0"
-    pip install "gunicorn==18"
+    pip install gunicorn
     pip install "django-compressor==1.4"
     pip install "django-statici18n==1.1.2"
     pip install "git+git://github.com/haiwen/django-constance.git@bde7f7cdfd0ed1631a6817fd4cd76f37bf54fe35#egg=django-constance[database]"
@@ -36,9 +37,10 @@ pre_upgrade() {
     pip install --upgrade python-dateutil
     pip install --upgrade django-pipeline
     pip install --upgrade "Django>=1.5.8,<1.6"
-    pip install --upgrade "Djblets==0.6.14" --no-deps --allow-external Djblets --allow-unverified Djblets
+    pip install --upgrade http://effbot.org/media/downloads/PIL-1.1.7.tar.gz
+    pip install --upgrade "https://github.com/djblets/djblets/archive/release-0.6.14.zip#egg=Djblets"
     pip install --upgrade  "Pillow>=2.6.1,<3.0.0"
-    pip install --upgrade "gunicorn==18"
+    pip install --upgrade gunicorn
     pip install "django-compressor==1.4"
     pip install "django-statici18n==1.1.2"
     pip install --upgrade "git+git://github.com/haiwen/django-constance.git@bde7f7cdfd0ed1631a6817fd4cd76f37bf54fe35#egg=django-constance[database]"