Fix bash if test to be safer

This will solve an issue like :" line 11: [: =: unary operator expected" in the case one of the operators are empty or missing.
Merge pull request #16 from mat-mo/master

Fix bash if test to be safer
Production build: build beta4
Test build: chown spamassassin folder
Test build: chown spamassassin folder
Production build: [fix] Correctly remove dspam
Merge branch 'test'
Production build: [bump] beta5 ?
Production build: [bump] beta5 ?
Production build: [bump] beta5 ?
Production build: [bump] beta5 ?
Production build: [bump] beta5 ?
Production build: [bump] beta5 ?
Production build: [bump] beta5 ?
Production build: [bump] beta5 ?
Production build: [bump] beta5 ?