Update gradle build script

bootRun can be started with production profile, dev profile doesn't optimize js/css/html files

fix #765
Unnecessary semicolon ";"

Apply for more lcode in more lines on index.html:

... href="javascript;"
Merge pull request #776 from BaleroCMS/patch-2

Unnecessary semicolon ";"
Removed useless "javascript;:" code
Merge pull request #775 from atomfrede/update-gradle-script

Update gradle build script
Revert "Removed useless "javascript;:" code"

This reverts commit 3c7a89ea8f9a34dc02169329fae86e7886307f1e.
Revert "Unnecessary semicolon ";""

This reverts commit 22d9333f1664dbc6778543cfd3551ff71bcfd1da.
Pre-configured the h2 console as mentioned in https://github.com/jhipster/jhipster.github.io/pull/20