Update xblock-lti-consumer with more Python 3 fixes.

requirements/edx/base.txt

@@ -151,7 +151,7 @@ lazy==1.1
 lepl==5.1.3               # via rfc6266-parser
 libsass==0.10.0
 loremipsum==1.0.5
-git+https://github.com/edx/xblock-lti-consumer.git@v1.2.2#egg=lti_consumer-xblock==1.2.2
+git+https://github.com/edx/xblock-lti-consumer.git@v1.2.3#egg=lti_consumer-xblock==1.2.3
 lxml==3.8.0
 mailsnake==1.6.4
 mako==1.0.2

requirements/edx/development.txt

@@ -194,7 +194,7 @@ lazy==1.1
 lepl==5.1.3
 libsass==0.10.0
 loremipsum==1.0.5
-git+https://github.com/edx/xblock-lti-consumer.git@v1.2.2#egg=lti_consumer-xblock==1.2.2
+git+https://github.com/edx/xblock-lti-consumer.git@v1.2.3#egg=lti_consumer-xblock==1.2.3
 lxml==3.8.0
 m2r==0.2.1
 mailsnake==1.6.4

requirements/edx/github.in

@@ -86,7 +86,7 @@ git+https://github.com/edx/crowdsourcehinter.git@a7ffc85b134b7d8909bf1fefd23dbdb
 -e git+https://github.com/edx/RateXBlock.git@2.0#egg=rate-xblock
 -e git+https://github.com/edx/DoneXBlock.git@2.0.1#egg=done-xblock
 -e git+https://github.com/edx-solutions/xblock-google-drive.git@2d176468e33c0713c911b563f8f65f7cf232f5b6#egg=xblock-google-drive
-git+https://github.com/edx/xblock-lti-consumer.git@v1.2.2#egg=lti_consumer-xblock==1.2.2
+git+https://github.com/edx/xblock-lti-consumer.git@v1.2.3#egg=lti_consumer-xblock==1.2.3
 
 
 # Third Party XBlocks

requirements/edx/testing.txt

@@ -188,7 +188,7 @@ lazy==1.1
 lepl==5.1.3
 libsass==0.10.0
 loremipsum==1.0.5
-git+https://github.com/edx/xblock-lti-consumer.git@v1.2.2#egg=lti_consumer-xblock==1.2.2
+git+https://github.com/edx/xblock-lti-consumer.git@v1.2.3#egg=lti_consumer-xblock==1.2.3
 lxml==3.8.0
 mailsnake==1.6.4
 mako==1.0.2