remove dependency to SpringBoot Mustache

It is no longer needed since we switched to Angular.

pdb-ui/build.gradle

@@ -18,9 +18,6 @@ dependencies {
   implementation lib_commons_lang3
   implementation lib_primitive_collections
 	
-	implementation(lib_spring_boot_mustache) {
-		exclude module: 'spring-boot-starter-logging'
-	}
 	implementation(lib_spring_boot_web){
 		exclude module: 'spring-boot-starter-logging'
 	}